Conditional URL Redirection using ISA & Apache

During the process of migrating wss2 to moss, we decided to put part of the sites on production whilelist leave some other stuff on old platform, hence there is a need to setup URL redirection.
the scenario is as following:

wss2.mydomain.com/currentSites ==> moss.mydomain.com/sites/currentSites
wss2.mydomain.com/oldsites ==> not diverting
wss2.mydomain.com/* (any other sites except the above) ==> moss.mydomain.com/*

this gave us a challendge to get this done, after playing with iis url rewritter, I realized that it is far less better than Apache URL_Rewritter so I decided to use apache.

for the conditional diversion based on path, I believe that can be done by using url_rewritter's proxy feature but it is bit cumbersome to set it up.

Noticing that ISA can publish sites based on paths, I created two web publishing rules to do the job: first one to publish oldSites and point it to the old server, second on to publish any other requests for wss2 domain and point them to the linux box.

within the linux box, apache is setup to divert all traffic based on the url pattern.
all currentSites URLs will have 'sites' added to them while other request will only get its host name replace.

we also believe that ISA might be able to take care of all this work, however since I am bit lazy to find it out and the current solution works fine. I guess we can live with it.