adduser.exe

Hi there, I have to write a PHP code for adding users to an email server. For this I use an application called adduser.exe from Ipswitch IMail Server 8.04. Can anyone tell me how I can use this file with a PHP code? Please note that the PHP runs on a different machine than the email software. So the function exec and shell_exec won't work. I have to execute the file on the mail server not on the web server. I tried it like this: <html> <form action="http:\\server-url\cgi-bin\adduser.exe method="post"> <input type="text" name="firstname"></input> <input>..... </form> </html> Should this work? If yes, how can I post the values to adduser.exe file? Are there other/better solutions? TIA Christian