command line

How do you pass a value to an Excel page when you open it?
Something similar is when you pass a value to a web page like:
http://www.dictionary.com/cgi-bin/dict.pl?term=cat
When the page loads the variable "tem" will equal "cat"
how do I do this? I want to create a page in Excel that
can completely change based on a value I pass from a web-based
link.
Thank you.