Load Balanced TS Pool

I have a question about an iRule that should be relatively simple. However I am not very good at writing iRules.

 

 

We have 4 Terminal Servers load balanced through the F5. We also use the F5 for Session persistence. This works very well inside our network. However users that come in through our SSL VPN have their user names shown in the persistence table as our domain name. I know why this is happening and we cannot get around it. What I would like to do is to round robin load balance any connections with this username and not maintain it in the persistence table. Can we do this with an iRule?