cPanel: email account creation. I need help making a PHP script.

Hey I have a website ( http://www.ppltalkin.com/ ) and the administration panel is powered by cPanel.
I want my members to be able to apply for an email address and have one automatically created for them on the spot!
I have squirrel mail installed and I have a cPanel password changer plug-in installed for squirrel mail.
I have tried to copy the code from the plug-in, change it a little and use it on a PHP/HTML page, however the script was heavy made to be integrated with squirrel mail, and sense my knowledge of PHP isn't that great, I'm having a hard time redesigning the script :(
Here's what the script does:
if I open my web browser and login to my cpanel account, then type

http://ppltalkin.com:2082/frontend/x3/mail/dopasswdpop.html?email=user1&domain=ppltalkin.com&password=123testing&quota=25

in the address bar, I have just created the email account user1, with the password 123testing and 25MB of mail space.
the script does the same thing accept instead of creating an email account, it will change the password of an existing account.
cPanel is located in a password protected directory of the server, so if I enter

http://ppltalkin.com:2082/frontend/x3/mail/dopasswdpop.html?email=user1&domain=ppltalkin.com&password=123testing&quota=25

in the address bar with out logging in first it will prompt me for a user name and password, and if I submit the username and password it will do the same has if I was logged in.
So what I need is a page that is a PHP html mix, that has a field for the new account name a password field, a password confirm field and a submit button.
The the php script would just collect the info from the fields, some how send

http://ppltalkin.com:2082/frontend/x3/mail/dopasswdpop.html?email=user1&domain=ppltalkin.com&password=123testing&quota=25

to the site and login.
However I'm not sure how to submit

http://ppltalkin.com:2082/frontend/x3/mail/dopasswdpop.html?email=user1&domain=ppltalkin.com&password=123testing&quota=25

to the site without actually taking the user to the site and I'm also not sure how to login with the php script.
HERE is the cPanel password changer plug-in http://www.squirrelmail.org/countdl.php?fileurl=http%3A%2F%2Fwww.squirrelmail.org%2Fplugins%2Fcpanel_pw_changer.1.3-1.3.tar.gz (it is written in PHP)
Any and all help would be greatly appreciated!
Thanks,
Holiday.