Yes, I've got an idea ;).

($thisresult) = ($teststring =~ /[aft][edt].[ftg]...v{2,3}/g);  

if ($thisresult) {
  if (!$lastresult) {
      print "Expression found\n"; 
  } 
} 
$lastresult = $thisresult;
[download]

Notice, I simply placed your $thisresult variable inside a pair of (). This is required as the regexpt would return array of matched values in list context. Previously, you were invoking regexp in 'scalar' context, which only gets you the total count of matches found.

Update: fixed code (saw the correct version after the original node was edited).

_____________________

# Under Construction
[download]