Launching the Desktop Application
Like in command prompt you must enclose path into quotes.
In case of VBScript it will be like this:
Dim appPath = """C:\\App\\Ellie Mae\\ApplicationName.exe""" ' three quotes at the beginning and the end
Also you may consider to add your application to Tested Applications and start it using TestedApps functionality: https://support.smartbear.com/testcomplete/docs/testing-with/tested-apps/index.html