Squid for HTTP Post

Hi there!!

I am new to Squid. I am investigating Squid to cache SOAP requests,
which are mostly HTTP POST requests. My questions are

1. Can I use Squid for caching HTTP POST requests? If not are there any
other open source/commercial softwares which would solve this problem.

2. Can I write "rules" in squid? For example if I want to cache my
"getCart" for "BobUser" and whenever "BobUser" does a "saveCart" I want
to flush getCart for "BobUser", is this possible with Squid.

Thanks a million.
Bob