ProxyPass irule query, dynamic rewrites

Hi All

I was wondering what is the best way to use the ProxyPass, we are currently running version 11.2.1 (HF 10):

(https://devcentral.f5.com/wiki/iRules.proxypassv10.ashx) for dynamic paths, I have it setup and working for static paths but have requirement for it to be dynamic.

I thought a regular expression would work, i.e. so any request which start with

site1.test.com/test-site/* rewrite to site2.test.com/test.web.portal/test/*, the traffic for site2 is handled by the F5 but via another pool:

"/test-site" =site1.test.com/test-site/(.*?)/=site2.test.com/test.web.portal/test/$1= /test/site2-HTTP-POOL

Thanks