W3C Markup Validation question

Hello... I was hoping someone could help me out some here. I am trying to run the W3C Validator at http://validator.w3.org/ and I am seeing a ton of errors related to cPath, the = sign and the & in the links I have embedded in my site.

If I want to reference the following for instance in my footer should I escape things like the & and = sign??? Seems odd, but I am no expert by any means.
<a href="index.php?main_page=index**&**cPath=2">Click Here</a>Here are some of the errors I am seeing:

reference to entity "cPath" for which no system identifier could be generated.
href="index.php?main_page=index&cPath**=**2"

reference not terminated by REFC delimiter.
…href="index.php?main_page=index&cPath**=**1"

entity was defined here.
<a href="index.php?main_page=index**&**cPath=2"...

If you are going to use an & symbol in your HTML, enter it as & instead.