add userProxy object in existing ADLDS record

Sorry for creating multiple thread on userProxy object.

I want to bind ADLDS instance with my domain account(AD DS) password. I knew I can do with proxy authentication. (http://technet.microsoft.com/en-us/magazine/2008.12.proxy.aspx).

I can add objectSID of AD DS user in ADLDS userProxy object, as mentioned in above article. But i am looking for add objectSID from AD DS account to existing ADLDS instance users. I know i can do it with FIM like tool, but i want to do without any tool.

Any help will be appreciate....