So you don't have trouble with freezepane?  Great I won't give up.

$TRUE is 1, tried using the following:

 = 1 ;
 = '1';
 = "1";
 = $TRUE;

Crashing is caused by the user having a copy of excel running, unrelated to the script, when the perl script is run. The involved files are unique.

So it would be best to know that excel is already running before the script is run. I could error out nicely, instead of locking up an orphaned version of excel.