Decode Parameter in URL

We need someone to figure out something for us. We are trying to automate a website, but reached a point were we need to reverse-engineer a parameter in a given URL. The basic URL is something like this. http://somesite/[login to view URL] So the value of "someparam" is the thing we need to decode. This string is identifying an item in "somesite" inventory and probably includes some other useful details. We are aware that it might be a dead end, BUT also we doubt that this server is using some kind of proprietary encoding/encryption, so it's possible that based on your expertise, you would be able to decode the string with a well-known algorithm web servers are used to employ for these cases. More samples may be posted at request.