How to get a drive letter during mount operation....

Hi,
I have a filter driver which intercepts the mount operation on drives.
Now I need to takeover only some set of drives, which is listed in the
registry. For that I need to get the drive letter of the volume, which is
being mounted. Could somebody suggest a viable solution to this problem.
Thanks in advance…

Sreejith S R
IBM Global Services Pvt. Ltd.
Golden Enclave, Airport Road,
Bangalore -17

Phone : 91-80-526 2355/7117 ext: 3024
Fax : 91-80-527 7374