So...I wrote this long post, and then somehow deleted it...stupid ipad :-)
Ok...so I did some digging. Check out the following website.
http:///www.team358.org/files/pneumatic/
Basically you can get 24 volts from one of the auxilary outputs on the power distribution board, and run it into a pneumatics breakout... See below.
http://www.andymark.com/product-p/am-0868.htm
You can not mix voltages. so you should run all 24 volt solenoids, or all 12 volt solenoids...mixing and matching = bad.
Thank you for asking this question. You forced me to look up something that I have been sort of avoiding and dealing with in sloppy ways.