Custom URL scheme and shell script question

This is kinda odd, but I've figured out how to make shell scripts run with a custom url. Is there any way to also pass information to the script?

Example: "tel:1234567890" tells the phone app to call that number. Let's say I have "myscript:1234567890". I can get it to run the script, but is it possible to get the number into the script as a variable or argument or something?

Caveat: I'm not a developer and don't know C++ so I'm stuck working with the script and trying different ways of making it take input, but nothing works. It may be impossible.

Well, actually, I was trying to do this with the Prowl app and after reading through the forums, I found that it doesn't yet pass the custom url. So even if you sent "tel:1234567890," Prowl will only open the phone app, not enter the number.

I'm already using Prowl notifications to run scripts on the phone (howto) and the next Prowl update is supposed to be capable of passing the info, so hopefully I will then be able to pass information to the scripts from the notification.

I found this app called Open URL which allows you to input custom urls and all their parameters and try to launch the application. I have no problem getting a shell script to execute with a custom url but no luck getting it to take any text input upon launch. It's looking kinda impossible.