Excel, equation to output either 'Agent name', "COPY", or "Not Found" - excel-formula

Question

I had an excel test that I didn't do particularly well on, but this one question had me stumped. I need an equation that takes the name in this list and outputs the agent name in 'first.initial' or "COPY" or "NOT FOUND"
Sheet 1:
Agent 
Adam.m
Agent 
David.e
Agent 
Joe.A 
Agent
Ben.B
Agent
Kat.C
Agent
Training.22
Agent
Admin
Convert these names: Correct output:
David Everit David.e
Joe a. Joe.A
Ben Ben.B
Sam p. NOT FOUND
Training 22 Training.22
David E. COPY
Kat Cathy Kat.C
David D. NOT FOUND
Adam.S NOT FOUND
The equation I submitted that my teacher said was wrong was:
=IFNA(IF(COUNTIF(Sheet1!A:A, A3)>1, "COPY", INDEX(Sheet1!A:A,MATCH(A3&"*",Sheet1!A:A,0))),"Not Found")

Answer 1

Well here's the thing.
You are checking the original data source for the name, pre-conversion. I must admit, the COPY was a bit misleading at first but I caught on later.
You are also wrapping the whole thing in a single logical... ISNA()... Your formula can only return TRUE, FALSE or an error from this.
Putting the wrapped ISNA() aside, this means that for your formula the majority of these entries are Not Found. True, if you instead had a list of data that had already been manipulated this would almost succeed. But you are checking for the "COPY" in the wrong data...
Your first task here would be to manipulate the data to the desired format of '[Firstname].[initial]' // So assuming that the first set of characters in the cell is always going to be the forename you can use a combination of something like:
=LEFT(A2,SEARCH(" ",A2)-1) - Gets the forname by returning the left-most characters to a length of the first space position minus 1.
=RIGHT(A2,LEN(A2)-SEARCH(" ",A2)) - Gets all characters to the right of space by determining the legth from the right as the total cell length minus the position of space.
You will need to perform a logical on the second scenario though as you want a single letter is it is a word or the entire thing if it is a number:
=IFERROR(RIGHT(A2,LEN(A2)-SEARCH(" ",A2))-0,MID(A2,SEARCH(" ",A2)+1,1))
So what i have done here is attempt to remove 0 from the string, if it is a number, this will succeed and return that number to us. If it fails it will produce an error and progress on to the second clause, giving us the single character.
You can combine these using simple string building or a concatenate clause:
=LEFT(A2,SEARCH(" ",A2)-1)&"."&IFERROR(RIGHT(A2,LEN(A2)-SEARCH(" ",A2))-0,MID(A2,SEARCH(" ",A2)+1,1))
or
=CONCATENATE(=LEFT(A2,SEARCH(" ",A2)-1),".",IFERROR(RIGHT(A2,LEN(A2)-SEARCH(" ",A2))-0,MID(A2,SEARCH(" ",A2)+1,1))
So now we are almost there, except that Ben and Adam are producing errors as there isn't a space character that can be found. We'll handle that error now so that we can move on to our search:
=IF(ISERROR(SEARCH(" ",A2)),A2,LEFT(A2,SEARCH(" ",A2)-1)&"."&IFERROR(RIGHT(A2,LEN(A2)-SEARCH(" ",A2))-0,MID(A2,SEARCH(" ",A2)+1,1))) - if you cannot find a space character then we will have the whole cell, otherwise, we will use the space to build the search term.
Now that we have the text formatted in the way that we want it, we can move forward to do the search, the order is important as we will need to first check our results from above for duplicates and print "COPY" where found, then look for the match and return it if it's there and lastly return "NOT FOUND" if we cannot find it.
We are going to need the use of the wildcard in order to satisfy the entry Ben. So let's show the logic first then throw the whole formula together:
=IF(COUNTIF($B$1:B1,[SearchTermFormula]),"COPY", - This part of the formula uses countif to check whether the search term already exists above it, returns "COPY" if so and will continue to the next part, the absolute referencing ($$) is important so that the range updates as you copy the formula down but keeps the first cell locked.
IF(ISNUMBER(MATCH([SearchTermFormula]&"*",Sheet1!$A$1:$A$14,0)),[SearchTermFormula],"NOT FOUND") - So this works to show the basic logical, again we use IF() to determine whether a match can be made as a number would be returned if so. We can then return the search term itself or "NOT FOUND".
A more elegent version of this part though would be:
IFERROR(INDEX(Sheet1!$A$1:$A$14,MATCH([SearchTermFormula]&"*",Sheet1!$A$1:$A$14,0)),"NOT FOUND"))
As it actually returns the result from sheet1 as well as making us use the [SearchTermFormula] 1 less time, using less resources.
INDEX() essentially maps the range as a 1 based array. What that means is the first cell in the range is considered an address of 1,1. You can think of it adding X and Y axis but 0,0 is outside the top left and the Y axis is inverted.
So we get it to index column A and MATCH returns the relative position, as the row's are equally sized, the relative position will be the row number we are after so we get the result returned or an error value, so IFERROR() leads us on to produce "NOT FOUND".
Putting all that together we have:
=IF(COUNTIF($B$1:B1,IF(ISERROR(SEARCH(" ",A2)),A2,LEFT(A2,SEARCH(" ",A2)-1)&"."&IFERROR(RIGHT(A2,LEN(A2)-SEARCH(" ",A2))-0,MID(A2,SEARCH(" ",A2)+1,1))))>0,"COPY",IFERROR(INDEX(Sheet1!$A$1:$A$14,MATCH(IF(ISERROR(SEARCH(" ",A2)),A2,LEFT(A2,SEARCH(" ",A2)-1)&"."&IFERROR(RIGHT(A2,LEN(A2)-SEARCH(" ",A2))-0,MID(A2,SEARCH(" ",A2)+1,1)))&"*",Sheet1!$A$1:$A$14,0)),"NOT FOUND"))
Sorry for the essay but I hope it helps you understand the scope