Redirecting part of a URL

I forgot to mention that the pool is going to be our openshift router so several applications will be hitting it.  We'll have separate WIPs for each app on our GTMs but the pool would be the same on the LTMs so the irule on the LTM i'd like to have any application.something coming in be able to switch the gtm.domain.com to the datacenter.domain.com keeping everything in front of it.  Our openshift engineer doesn't want to have to add the .gtm.domain.com route to each application.