This is the only one that comes up on Newegg: http://www.newegg.com/Product/Product.aspx?Item=N82E16814125281. Reviews are middling, and I'm not even sure you could get to the HDMI port in your case.

Probably just more worth it to toss the machine and get something else. AGP is the deadest of the dead standards. You can probably get more ISA cards than AGP cards these days...

I am the Doctor, and THIS... is my SPOON!