FN key alternative when using external keyboard

I have my D600 plugged into the D/Dock with an external PS/2 keyboard and all is well.

But there are some functions (such as switching wireless on and off) that when using the D600s keyboard, are achieved by pressing FN and another key (F2 in the case of wireless).

Obviously the external keyboard does not have a FN key so my question is:

Is there an alternative set of keyboard combinations that can be used in the absence of the FN key on the external keyboard.

OR

What would be nice is if Dell produce an external PS/2 keyboard (not USB as it goes through a KVM switch) with a FN key.

Thanks