URL rewrite question

[Sriram Chavali]

I am trying to rewrite URLs using haproxy's reqirep directive. The url that I 
am trying to rewrite is of the pattern
/action/register?param1=foo&param2=bar&param3=baz

The URL that I want to be rewritten is 
/newaction?param1=foo&param2=bar&param3=baz on the condition that whenever 
param2=bar

The ordering of the query string parameters can be random, i.e param2 could be 
the 1st parameter or the last one. 

Can somebody please help me?

Thanks
Sriram