C# create excel sheet late bound

Using winforms, C# FW4.5 to open an excel sheet with late bound, like this:

objExcel = CreateObject("Excel.Application") 

Now I want to use the InvokeMember method, but I don't know all the members of excel I can invoke. For example, I know I can call it like this: InvokeMember("Close",... in order to close excel, but where can I find list of all the members I can invoke and what each one of them does?