[Zinc-fans] Making your own subset

[Samo Turk]

Dear zinc-fans,

I noticed that generation of user subsets doesn't work. 
What is the easiest way to make your own subset? I downloaded compounds
of 4 different vendors (~million compounds) from ZINC and now I'd like
to extract those that fall in certain logP and molecular mass interval.
I tried to write a bash script which uses Open Babel for calculating
logP and molecular mass and then extracts relevant compounds, but it is
painfully slow. It would need few weeks to filter all compounds. Has
anyone written more effective script or knows of a program that can do
this in reasonable time.

Best regards,
Samo Turk