Extracting Data From A URLEncoded String

I am trying to add a feature to our inventory that will pass the current URL to a second site so that I can return to the original site later through a redirect. Basically, it is intended to work like this - you do a search, and are taken to a page where you can view the records.

You click on a record to view it and/or update it, and then you are returned to the original search results. I am having some trouble, and am hoping that someone can help me out.

I am placing the values that I want to keep (original URL, search terms, sort order, page number) into a string, and then using Server.URLEncode to encode it: Code: