No, I guess it isn't working.

'Set the string you want to find in the file.
strValueToFind = tmp

'strValueToFind will be replaced with a line from the file, so it looses it's original value.
Line Input #intFileNumber, strValueToFind

' this line doesn't make any sense, you check if the line you just read from the file can be found in the filenumber (probably just 1)
If InStr(intFileNumber, strValueToFind) > 0 Then