Retrieving Exchange User
 

Hi,
I have the contact number and I need to retrieve the details of exchange user.
So I am retrieving all the exchanger users and comparing the phone number.But this is taking too much time as i have more than 150000 users to search.I tried to find out a way to connect to advanced find option of the address book,but it is not possible according to many of the posts i read.So i would like to know any other way to retrieve the details in an easy manner.

Thanks in advance,
Harikumar