Include client IP address in rewritten URL

[Shawn Heisey]

I am trying to use haproxy 1.4.8 to replace an apache URL rewriting 
engine that crumbles under load.  I have to duplicate the following part 
of it:

&ipaddr=%{REMOTE_ADDR}
The IP address is not part of the original URL, but it must be included 
in the rewritten one.  Looking at the documentation, I cannot figure out 
how to do this.  Can anyone help?

Thanks,
Shawn