exec php.exe in windows

["Dave Kennedy" <davek@xxxxxxxx>]

Env:
Windows XP
PHP 4.3.10 (cgi-fcgi)
 
I am trying to capture the html output of Balance.php to a file:
The code loops over <month> and <branch> to build up a report in
export/Balance.html
 
exec('c:\php\php -q Balance.php export=all branch=<branch> month=<month>
login=admin password=admin >> export/Balance.html');
 
This command works in Linux when called from a web page.
In Windows it works from the command line 
but from a web page it hangs - a cmd and php process are left running in
the Windows Task Manager
 
Any help would be greatly appreciated