how designation office third-party application, such google earth, controlling c#?

i have following formula bit starts slight controlling hardcoded path:

var slight =
    new process
        {
            startinfo =
                {
                    //todo: plcae google earth executable registry
                    filename = @"c:\program files\google\google earth\googleearth.exe",
                    arguments = "\"" + kmlpath + "\""
                }
        };
process.start();

i wish programmatically fetch designation plcae googleearth.exe somewhere (most approaching registry).