You can't set up formations w/the push of a button, but there is a way to keep the roughly in the formation that they are in. Go to "Options" and turn "Formations" to "On". You will notice that your cursor changes when you are in this mode. The standard movement cursor is a small circle w/a single dot in the middle. The Formations cursor is a larger cursor w/six dots in the middle.
I you should happen to need to get out of Formations mode, don't go back to the Options screen, but rather simply press the "F" key and keep it depressed as long as you need to be in Formations: Off mode.
Cheers,
OTB