GMap.NET.GMapControl with custom map provider?

you need to trace tile urls using fiddler, then copy existing map provider class and modify urlformat, unless this provider use some esoteric projection, thats it, otherwise you need to know the projection details and make a custom projection class, check the source at https://greatmaps.codeplex.com/SourceControl/latest or github.

There is a WMSProvider class in:

WMSProvider

It works fine, by changing szWmsLayer and CustomWMSURL vars.