URGENT: cam pulley locking

[Konstantin Bogach]

Hi list.

I am on the middle of changing timing belt.  I bought crank pulley
locking tool but I thought I can get away locking cam pulley with big
slotted screwdriver.  Can not do that with one pair of hands! Rather
than risk neighbor fingers I would like to buy special tool from Zelenda
or Snap-On unless you can give me a better idea then holding screwdriver
against threaded pin next to the pulley.
I will appreciate letting me know Audi part number (dealer's phone is
busy all the time)   and Snap-On stock #  for the tool or better way to
do it without having to buy it.
Who is giving better price?

Thanks.

Konstantin Bogach
200tq '89
200tqw '89