Yes there is a way to do it. This is the easiest way to do it. Make a copy of your UO folder in the "call of duty game of the year edition folder" and rename it to "copy of UO" (or whatever you like.) then make a copy of your coduomp.exe and rename it like you did your UO folder. Now copy and paste the "copy of coduomp.exe" to your desktop. So now you will have to UO icons on your desktop, one is the originial and one is the copy. This worked on my XP pc but didnt work on my machine with windows 7. I got a buffer overrun with my windows 7 using this method.
For my windows 7 I did this.
Copied my entire "Call of duty game of the year edition" folder and pasted it in program files. Rename it to "(Copy)Call of duty game of the year edition" then went in copied the coduomp.exe and pasted that to my desktop. Either way works just the second method taks a little longer due to more files to copy. If you have any questions just ask.
Jim