is this possible?

I would like to have someone create the following:

- the user installs the program...
- when in IE, Netscape, or FireFox etc, and they right click, a menu will appear with various options which they've set in an admin panel or something.

the basis is that I want them to set custom fields in the admin such as "firstName". Then when they're in a form on a webpage, and right click they can say "autofill > firstName" - that will then get the value stored from the admin panel and put it in the form.

Is it possible across browsers??
anyone had any experience with this sort of coding? I am guess it'd be in C++ or similar?

thanks