Data Decrpytion using Applet/Key & auto-input into php form field

I have done a web form using php to input data into MySQL. However, the client requires that their staff to be logged into their intranet to be able to be directed to my site to fill in the form. Their data (email and name) will be encrypted and sent via url to my form. The client has already provided me an applet, the key and a html consisting of javascript for incorporation. Unfortunately, I am not very familiar with javascript so I can't translate that decrypted data into a php form field. I have already managed to GET the data from the url but need a programmer who is willing to help me complete the decryption of the encrypted data and have it reflect in a hidden form field or (even better) to post it to mySQL database.