As aminuts says, I don't think it's possible. But here's a little script to speed up the process. Load the script and, with your polymesh in Edit mode and groups showing, hold your mouse over a group point (it works best if the little red square snaps to a point) and press the 5 key. A crease will be applied to that group and you can move on to the next.
Thanks very much for your help. I'll check that crease script out.
The thing is it isnt easy when i have 96 poly groups!
Why do i have 96 polygroups heh ? , well im having that problem where I need to crease hard edges. Coming from a wings+maya background the most straightforward way is to auto unwrap in wings (takes 2 ticks), then spread each uv shell into its own 0x1 space in maya ( again takes two ticks with a script). This gives me the 96 poly groups.
I know its possible to optimise and use far less groups by manually moving around all the different uv peices by hand, but i have 10 4k poly characters to do and it takes much time to ensure I dont have two adjacent shells in the same poly group.
If you Shift-click the ZB Crease button you'll crease ALL EDGES of the visible mesh, so if the whole mesh is visible, the whole lot will be creased. This may work for you if you're importing a low res model and adjust the Crease level slider appropriately. Remember creases are ZB specific. They'll export but if you export a low res mesh and subdivide in another program they'll lose their effect.