I can certainly say that the idea scenerio is to fix the code so BIGIP doesn't necessary have to mask the issue.
However, is a quote by Joe, that I found that may help you
Posted By Joe on 03/30/2007 1:27 PM
This is overlooked most of the time, but if you want a simple string replacement, the easiest solution is to use a Stream Profile associate with your virutal. There are no iRules involved. Just create a stream profile with the Source value as "www.somedomain.com/someuri" and the Target value as "www.somedomain1.com/somenewuri" and apply it to your virtual.
Keep in mind that the stream profile will only work with fixed strings, regular expressions and wildcards are not supported.
-Joe