Setting PictureURL property of sharepoint 2010 User Profile Synchronization by BCS Connection

I have a requirement that client stores the Urls of User Photos in SQL server database in a table against Account Name.

I tried Using BCS connection to set PictureURL property but when i map this property to the BCS connection, the attributes dropdown shows blank.

I am using sharepoint 2010 build in the farm 14.0.4762.1000.

Any solution to this is greatly appreciated.

Thank you,

vm250091.