As usual, append to the end of file and call it
E.G.
;Creates the temp file for text operations
$TempFile = @TempDir & "\" & _RandomText(10) & ".tmp"
$TempFile = FileOpen($TempFile)
Code:
Func _RandomText($N)
;$n is the lenght of string.
If $N < 1 Then Return -1
Local $COUNTER, $ALPHA, $RESULT
For $COUNTER = 1 To $N
If Random() < 0.5 Then
$ALPHA = Chr(Random(Asc("A"), Asc("Z") + 1))
Else
$ALPHA = Chr(Random(Asc("a"), Asc("z") + 1))
EndIf
$RESULT = $RESULT & $ALPHA
Next
Return $RESULT
EndFunc ;==>_RandomText






