You're half in luck!

I got a device called a RedRat2 a long time ago from a web site which is sort of what you are looking for. It plugs into the serial port and can learn consumer IR and play it back very reliably. I wrote a Windows based OCX and Learning on screen remote for it. You should be able to use the OCX to create a Web page of what you want. I have a small VB monitor which listens at a specific port, when it gets an IR code (plain text) it sends it to the device.

I have it connected to my PC upstairs and then Powermids send the IR to the stack in the living room. It works well with the empeg and all other devices I have tried (around 18).

I use it with my laptop and a wireless NIC to control everything in the house!

Look at the site www.redrat.co.uk for all the other Sw available.

MK2 Red S/n 949