Hi Matheen,
You can alternatively create another password policy which will apply of part of user directory, and don't give any expiration or details to it, also in Advanced Tab give the priority to it as 1 and give the priority to other password policy which applies to complete directory as 10 or higher, this will make the password policy applying for complete directory to apply first and will not be applied top policy applying for part of user directory.
Evaluation priorities range from 0-999, where 999 is the highest.
Hope this helps.
Regards
Vikas