Wierd connections

Hi,
I have a bluetooth headset, bluetooth enabled pda and a bluetooth
phone.
Here is what i want to do.

i want to use my pda as a phone only when i am using the bluetooth
headset.
So i can keep my phone in my pocket but still use my pda to dial and
talk using the bluetooth headset i have...

is it possible to make such connetions with the headset...because it
will have to be connected to both the pda as well as the phone?

any ideas ?

Rishi