What software do you use?

If you use isboxer, there are some premade formation keymaps that come built in - you just have to map them. There are a lot of guides on these forums that talk about this.

Just do a search for "Formation" on this site.

Or check out this guide.

http://www.dual-boxing.com/showthrea...ight=formation

(Or look at the post above mine - much better at explaning!)