ATI makes a remote called. "Remote Wonder II"
I've got one and it works really well with Winamp & Windows Media Player. It also obviously works with all ATI media players.
There are also several plugins available to allow it to work with other programs too. This is the cheapiest solution.
Here is the ultimate website for all remotes... There are plenty listed here with full reviews, many can be used with PC's.
Ranging from $30 to $1000
P.S if you do get a remote for your PC, there are special X10 USB drivers that you must install inorder to get the remote to work.
PM me if you need help locating them.