Parkandannounce()

is it possible to achieve one step parking with the use of parkandannounce() application?
using parkandannounce() i am able to get parkingslot number through ${PARKEDAT} but parking takes two steps…one for transfer…and one for reaching the parkandannounce() application…
what i see is for one step parking we make the use of features.conf and the dialplan uses the inbuilt park() application…i am trying to feed parkingslot into some variable…i am not able to do that while using park()…
so how to get the parkingslot number into some variable alongwith parking the call in one step?? can anyone please help me out???