Integrating jarsigner in wp themes

Hi WP Genius,

Thanks to all you contributors for making WP the easiest way to create blogs and websites.

Well, for a naive person like me, it is a blessing in disguise.

Now the query:
I have created a website using WP themes. I need to integrate a third party jarsigner which will print my logo and a serial numberon the pdf documents uploaded by members.

Pl. guide me how I can achieve this.

Thanks in advance.