esi question

[Chris Hecker]

I'm trying to figure out if I can use ESI to solve a problem, and I'm 
wondering if there's a way to take parameters from the main url and pass 
them to the ESI included url, so like:

http://blah.com/foo?bar=true

and inside, I want "?bar=true" to be passed to the ESI.  Do I need to do 
this manually with regexes and whatnot in the vcl, or is there a way to 
automate it?  I've seen something about last-mod-time or something being 
passed, but it wasn't clear from the docs...

Or, am I missing something and this is a dumb idea?

Thanks,
Chris