I did find some conductive coating spray on amazon that should work perfectly. It is designed to be sprayed inside of electronics housed in plastic to reduce emi/rfi.
Then what?
Off the top of my head - ( I haven't ask advice or researched it) - I would then want to make a very good electrical connection to that conductive layer, and connect it to a very good ground. I might even want to use coaxial cable as that ground lead - thus being able to shield the lead to ground all the way.
You might be able to simply jumper a lead from the conductive layer, to the metal case (whatever is grounded) of the computer's power supply, instead. That might do it. Not sure....
I still suggest that you ask people that actually do this sort of thing, all the time. That is: deal with sensitive receivers, in close proximity to computers that generate all sorts of rf interference. While in the non-commercial, home-brew type envirorment (meaning: figure out how to do it yourself, without unlimited funding by the employer. )
Go here:
http://www.eham.net/ehamforum/smf/index.php/board,7.0.htmlThat's an example.
That section of their forum is dedicated to computer stuff.
You could sign up and post there.
On the flip side, THEY might like to have patio sign up there, and advise THEM from time to time.