mIrc tip from Greg Abcarian:

To get the rollbot to work in mIRC there is a file in mIRC directory called Aliases.ini. Open that file and insert these commands at the end of it, then save. You might have to restart mIrc for them to work.

n11=/f3 /msg rollbot roll # 3
n12=/f2 /msg rollbot roll # 2
n13=/f1 /msg rollbot roll # 1