IRule to manipulate an LDAP binds.

We have an application that is set up to talk to our LDAP servers. This application will use the logged users ID (From AD) to make a bind request to LDAP (AD LDS). the issue is a users ID in AD is slightly different in to their ID on the LDAP and so basic binds fail. What I want to do is create a simple iRule to ready the BIND request and manipulate the ID/DN of the user so it matches what LDAP will have. This is simply adding a character (always the same character) to the presented ID before passing it on to the LDAP. Does anyone know of as basic iRule to perform this?

Thanks