actually the $ donates a variable of any type.
i got this working in the end
the final code is as follows
[VBA]for ($counter = 0; $counter < strlen($GetText1); $counter++){
$Decrypt1 = $Decrypt1 . chr(ord(substr($GetText1,$counter,1)) -15);
}
for ($counter = 0; $counter < strlen($GetText2); $counter++){
$Decrypt2 = $Decrypt2 . chr(ord(substr($GetText2,$counter,1)) -15);
}[/VBA]