This forum isn't really meant for specific-issue technical support. Feel free to post a thread like this on
stackoverflow or the
public issue tracker (depending on whether you think a solution exists and you just don't know it, or whether you think something is going wrong according to what docs say should happen in a given situation).
Also, you've posted this on Google App Engine group but it seems to be related to Apache mod_rewrite. If you're looking to implement something similar in App Engine, you may find
this article helpful. If this isn't related to App Engine, I recommend posting this question with
this stackoverflow tag.
I hope it helps. Cheers!