difficulty with "for" loop

I think you need to recognize the distinction between 2 different variables iMyNumber and iMyNumber2. To help facilitate this, review this very similar code:

Sub Example()
Dim iLoop As Integer
Dim iCount As Integer

iCount = 0 'starting value

    For iLoop = 1 To 100
        iCount = iCount + 5
    Next iLoop
    
MsgBox (iCount) 'gives ending value after adding 5, 100 times

End Sub

Hmm. I understand the two variables, but I don't understand why you can put "imynumber" in the first example and it will add 1 each time but it won't do the same if I put "imynumber2" (without the +1).