check out
http://www.homecontrols.com/cgi-bin/...ith-Rod-Center
and I was able to get black out drapes from WalMart for a few bucks. I plan on using the black out shades as a liner and have more attractive curtain showing in the theater.
I don't know that I'd trust just adding and mounting a motor to existing curtain rod.
I'm looking at the above link because I need IR control. There are others out there if you just want RF, check out ebay, or do a google search for (Remote Curtain). Lots of results.