Communicate C# with JavaScript by CGI

I have written a Windows Forms application, which I would like to run by clicking a button on HTML page and JavaScript script inside.
I have red that I can communicate this two things by CGI, but I don't really know how it shoud work.
On my WinForm app I have method called "ScanDefault()" (my app works like a scanner, but in the future I want to upload scans to the server).
I thought that I could call this ScanDefault() method by js, but I don't know if it is possible.
Thank you for your help