Excel 2013 advanced date range lookup using sumproduct - excel

Question

I am new to Stackoverflow, so please let me know me if there is not enough information. I have had many helpfull insights by using StackOverflow in the past, but I cannot find any helpful thread online, so I hope you can help me.
I've been working on a excel (2013) problem for a while now. I am trying to build a marketing agenda to store and keep track of our mailing campaigns. The campaigns themselves are send via another system, but we miss the ability to plan our mailing campaigns in advance. Since we are active on different markets in Europe, we decided to have a general mailing (for all regions) and a region specific mailing campaign (both are in the same agenda). Besides this we also want to display the mailing focus (different brands). It is my idea to return this as visual as possible (to make it usable for all users). I have add a small picture to show my desired end-result (however without any data at this moment).
At this moment, the users are going to use a (Google)form to enter the campaign information and this data is downloaded to the worksheet (by doing so all users can add new campaigns and everyone always has access to the most recent data). This part works well.
I am using a helper sheet to check if the dates fall in a campaign range, if it does fall in a campaign range it should return the mailing ID (also the row number). I have another form which uses this data to search for the right brand and displays visually (with a lot of conditional formatting).
The problem arises in the helper sheet (when I check if a date fall into a campaign range). I have been able to get it working (more or less) with the following formula:
=IF(SUMPRODUCT(--(CountryHelper!$C$2:$C$100<=$B4);--(CountryHelper!$D$2:$D$100>=$B4);RIJ(CountryHelper!$C$2:$C$100))=0;"";INDEX(CountryHelper!$A$2:$A$100;SOMPRODUCT(--(CountryHelper!$C$2:$C$100<=$B4);--(CountryHelper!$D$2:$D$100>=$B4);ROW(CountryHelper!$A$2:$A$100))))
In this formula, CountryHelper!C:C is referencing the StartDate of the mailing campaing. D:D will reference the column of the EndDates and A:A has the mailing ID. Cell B4 is the date that needs to be checked.
At first it looked this worked perfectly. If a date fell in a date range then it would return the ID. After a little playing around with this a problem came to light. It only works with non overlapping dates, once dates overlap excel will add the row numbers together and it would not work any more.
Is it possible to get the sumproduct formula working and returning only the first ID. I am aware that I then have to make another 2 formulas which return the second and third ID ( I am certain we do not get more than 3 overlapping dates). This is also the part where I get lost. I've tried to use a MIN and MAX variation wit the following sumproduct formula:
=SUMPRODUCT(--(CountryHelper!$C$2:$C$100<=$B4);--(CountryHelper_RSEU!$D$1:$D$100>=$B4);ROW(CountryHelper!$C$1:$C$100))
This will return either a 0 (with MIN) or 100 (With MAX). I think this is caused by the formula (for now it only searches the first 99 rows). I also have ventured into VBA / UDF to get this done, but as I understand it this is not possible.
Anyway, I am sorry for the long story, I hope that my problem is clear and you can help me. If you need any more information.
Thank you!
empty Marketing Agenda overview

Answer 1

The SUMPRODUCT is a kind of swiss army knife Excel function. But here it is wrong because, as you already have seen, it really calculates a SUM at the end. Mostly it works because it first multiplies the 0 or 1 of the conditions with the row numbers so only the row numbers which fulfills the conditions comes into the sum. But if two or more row numbers fulfil the conditions then they were added together.
Are you familiar with array formulas? The following array formula should be what you want:
{=INDEX(CountryHelper!$A$2:$A$100;MIN(IF((CountryHelper!$C$2:$C$100<=$B4)*(CountryHelper!$D$2:$D$100>=$B4);ROW(CountryHelper!$A$2:$A$100)-1)))}
To create a array formula put the formula into the cell without the curly brackets and then press [Ctrl]+[Shift]+[Enter]. Then the curly brackets should appear automaticaly.
How it works:
{IF((CountryHelper!$C$2:$C$100<=$B4)*(CountryHelper!$D$2:$D$100>=$B4);ROW(CountryHelper!$A$2:$A$100)-1)}
Gets a array of row numbers or FALSE {FALSE, rowNumber, FALSE, ...}. If both conditions are fulfilled then it gets the row number - 1, if not then it gets FALSE.
The MIN function then gets the smallest (row number - 1) from this array.
The INDEX then indicates this smallest (row number - 1) which fulfills the conditions.
It subtracts 1 from the row number because your INDEX range starts at row 2. If the row number 2 fulfills the conditions then it is the index 1 within this range, if row number 3 fulfills the conditions, it is the index 2 and so on.
Why it only works as array formula? Because the IF function do not creates a array by default even if their "Value_if_true" is a range. Within the array context it does exact this.