How do I exit a "do while" statement - excel

Question

Sub FindValue()
Dim firstAddress As String
Dim Expense As String
Dim rRange As Range
Dim FirstrngFnd As Range
Dim x As Integer
Dim y As Integer
Dim z As Integer
Workbooks.Open FileName:= _
"D:\My Documents\Excel Files\AA Credit Card\1008.xlsx" 'A worksheet with several columns - Column G (Column 7) is a list of "expenses".
Workbooks.Open FileName:= _
"D:\My Documents\Excel Files\Credit Card Analysis.xlsx" 'A worksheet with "expenses" listed in random order in Column A (Column1)
Windows("Credit Card Analysis.xlsx").Activate
ActiveWindow.Panes(1).Activate
Expense = Application.InputBox("Select the required expense from Column A") 'Pick an "expense" from a list in Column A
'Open the first file in the first folder
Windows("1008.xlsx").Activate
ActiveWindow.Panes(1).Activate
'Establish the first and last rows in Column A (which contain a list of dates by increasing date): required to establish the search range
Set rRange = Range("A1", Cells(Rows.Count, 1).End(xlUp))
For Each rCell In rRange
If IsDate(rCell) Then
rCell(2, 1).Select
Exit For
End If
Next rCell
x = (ActiveCell.Row - 1) 'This finds the FIRST row in the file with a date in it
y = Cells(Rows.Count, 1).End(xlUp).Row 'This finds the LAST row in the file with a date in it
My_Workbook = ActiveWorkbook.Name 'Holds the current Workbook name
'Move over to the "analysis" column (G) (Column 7)
With Worksheets(1).Range(Cells(x, 7), Cells(y, 7))
Set FirstrngFnd = .Find(Expense, LookIn:=xlValues, LookAt:=xlPart) 'Finds the first occurrence of "expense"
If Not FirstrngFnd Is Nothing Then 'if the "expense" isn't listed then goto Line400
firstAddress = FirstrngFnd.Address
Do 'DO WHATEVER IS REQUIRED IN THIS SECTION: FROM "DO" TO "Set FirstrngFnd = .FindNext(FirstrngFnd)"
z = FirstrngFnd.Row
FirstrngFnd.Value = "Mike" 'IF YOU OMIT THIS LINE THEN ALL THE VALUES REMAIN AT "expense", SO THE PROGRAM JUST GOES ROUND (AND ROUND) AGAIN.
Set FirstrngFnd = .FindNext(FirstrngFnd)
Loop While Not FirstrngFnd Is Nothing
End If
End With
End Sub
If I remove the line "FirstrngFnd.Value = "Mike" then the values in Golumn G never change so when the program gets to the end of the file, it just goes round again.
How can I get it to recognise it's been through the file once, and to move on?

Answer 1

Please, modify:
Loop While Not FirstrngFnd Is Nothing
in this way:
Loop While Not FirstrngFnd Is Nothing And FirstrngFnd.Address <> firstAddress

Answer 2

Find in an Endless Loop
This covers the case when you are using the Find method (incl. FIndNext) to find all occurrences of a value in a range, but you don't want to change them and you also don't want to end up in an endless loop.
To simplify, the procedures use Sheet1 (CodeName) and the range "A1:A3" and "Yes" as the criteria.
Copy them into a new workbook.
Test first both procedures without values, then put in some "Yes" values (without the double quotes) in the cells. You can also change the range to e.g. A1:A10, to better understand.
The Code
Option Explicit
' To exit the endless loop, press and hold down the ESC key.
Sub testEndlessLoop()
Dim rng As Range
Dim cel As Range
Set rng = Sheet1.Range("A1:A3")
Set cel = rng.Find( _
What:="Yes", _
After:=rng(rng.Cells.Count), _
LookIn:=xlFormulas)
' Assuring that a cel containing "Yes" has been found. Once it has
' been found, find will always find an occurrence of "Yes" whether
' there is one, two or three occurrences in the range,
' which will result in an endless loop (Do Loop).
If Not cel Is Nothing Then
' A cell containing "Yes" has been found.
Do
MsgBox "Found ""Yes"" in cell '" & cel.Address & "'."
' Find the next occurrence of "Yes"
Set cel = rng.FindNext(cel)
' 'While Not cel Is Nothing' is redundant because 'cel' will
' never be 'Nothing' anyway, which is ensured previously with
' 'If Not cel Is Nothing Then'.
Loop While Not cel Is Nothing
Else
' A cell containing "Yes" has not been found.
MsgBox "No occurrences found."
End If
End Sub
Sub testWorkingLoop()
Dim rng As Range
Dim cel As Range
Dim FirstAddress As String
Set rng = Sheet1.Range("A1:A3")
Set cel = rng.Find( _
What:="Yes", _
After:=rng(rng.Cells.Count), _
LookIn:=xlFormulas)
If Not cel Is Nothing Then
' A cell containing "Yes" has been found.
' Write the range address of the first found occurrence to a variable.
FirstAddress = cel.Address
Do
' This is where you do stuff when "Yes" is found.
MsgBox "Found ""Yes"" in cell '" & cel.Address & "'."
' Most often you don't want to change the found cell,
' but you want to change another cell in the same row,
' e.g. write to the cell in column 'B'.
cel.Offset(0, 1).Value = "Found a ""Yes""."
' This is where you do stuff when "Yes" is found.
' Find the next occurrence of "Yes"
Set cel = rng.FindNext(cel)
' Again, 'cel' will never be 'Nothing'.
Loop While cel.Address <> FirstAddress
Else
' A cell containing "Yes" has not been found.
MsgBox "No occurrences found."
End If
End Sub