string manipulation of OAM Policy response value

Hi,

I have a protected application with a response defined on the protected resource as below:

             username(response header name) =  $user.userid  

So, I returning a header variable with name "username", and the value is fetched from the identity directory.

In my case, lets say user with username "012345" has logged in, then the response variable will be username=012345. I want to perform a string manipulation on the value and send 12345,

that is , username=12345, by removing '0' from the value fetched from the directory.

Is this possible to achieve at OAM side?

Thanks,

Malli.