Is there a way to create a listener in a Windows Form application for a custom protocol (URI Scheme)?

Question

I was able to create a URI Scheme in the Registry [HKCU\Software\Classes] for my VB.NET Windows Form application.

If I use the new URI [CSIPOS:] and then a string my application knows to open the application and read the arguments in the string.

The problem I'm having is if the application is already open and you use the same CSIPOS: link then nothing happens.

Is there a way to build a listener or a way to get the Custom Protocol URL to work while the application is open?