Internet Explorer Modification - freelance

Basically, here's what I need: My team work with lists. We need to be able to install an Internet Explorer add on that can execute a regular expression replace style modification of the code on certain URLs we list. Expression provided. The second thing that the program would need to do is load the URLs from these lists (regular expression provided to find them) and load them, subjecting them to some basic logic loops (pseudo-code available), returning some information on each, which would be fed back to the site via JavaScript somehow. (If it's possible to call a JavaScript function from a browser mod that would work.) Very detailed PHP-style (only language I know) pseudo code will be provided. I just need the translation into C# and the experience with browser modifications.