If you do a google search, you will come up with some info on that dll and Omega. I didn't read through the hits to see how useful they are, but it may be a good place to start.
I've located the dll in my Mesadll directory for you. I'm not sure where Tradestation is looking for it (probably windows/system or windows/system32. Anyway, I've uploaded it so you can download the file. I'll leave it there for a day or so so you can get it.