If you use Vista, you can use the "start /affinity" construct in a command (batch) file:

[code:1]wow1.cmd:
start /affinity 1 c:\games\world of warcraft drone 1\wow.exe[/code:1]

etc.

I'm not sure how you do that under XP, but (with the Pro edition at least) you can set the affinity of an already executing process from the task manager.