How could I have two weapons in 1 swep

There is a riot sheild on and I thought it would be cool if you had a stunstick or batton with it so you can block and hit.

I have just finished creating the stunstick swep (I may change it when I find a batton model)

What I am stuck at is how I can allow use of the stunstick while the riot sheild is equip.

Any help?