Use VBA to search text file for string and return line number

Question

I'm trying to search through a txt file for a certain string using a Do While Not EOF loop and then either return or just set a flag of that line number whenever the string is found.

I'm extremely new to VBA with access. What would be the most basic way to go about doing this? I'm using Access 2007

Thank you

Here is what I have so far, I pulled it from various examples online to try to get it to work.

    Dim myFile As String
   Dim text As String
   Dim textline As String
   Dim posIAV As Integer

   myFile = "file path"

   Open myFile For Input As #1

   Do While Not EOF(1)
   Line Input #1, textline
   text = text & textline

   Loop

   Close #1

   posIAV = InStr(text, "IAVs ADDED in this release include")

   MsgBox (posIAV)

Answer 1

Just replace MyString below with whatever it is you're looking for.

   Dim myFile As String
   Dim text As String
   Dim textline As String
   Dim posIAV As Integer
   Dim Ctr as Integer
   Dim Ctr2 as Integer

   myFile = "file path"
   Ctr = 0
   Ctr2 = 0

   Open myFile For Input As #1

   Do While Not EOF(1)
   Line Input #1, textline
   text = text & textline

   ' Increment Ctr since you're on the line now
   Ctr = Ctr + 1

   ' Check the current line to see if it contains the string we're looking for
   ' If it does, set Ctr2 to be the current line number
   If textline like "*MyString*" Then
      Ctr2 = Ctr
   End If

   Loop

   Close #1

   posIAV = InStr(text, "IAVs ADDED in this release include")

   MsgBox (posIAV)