Hi greneeb,
This forum is rarely visited at the moment, and new registrations are blocked.
I would normally suggest that you ask over at Cadtutor.com where you'll find many of the regulars who used to help here, but I see that you have already asked there.
I'm afraid that I agree with BIGAL, I'm pretty sure that it cannot be done.
A dialogue box is displayed to take input to a command that is being executed.
Until that input is given and the command closed (or canceled) then you can't start/use another command.
Im intelligent enough to know that I dont know everything; but I'll tell you all about it anyway.