Checking Word Format From Visual Basic

Is anybody aware of how to check the format of a document before you open it in Visual Basic? I am opening Microsoft Word documents from a Visual Basic application but want to know the version of the document I am opening. I am trying to avoid the case where somebody has inadvertently named an executable or excel document with a .doc extension and then attempting to open it and have it error out. I am assuming there is a Visual Basic or WordBasic call that will tell you if the document in question has a valid Word format or not. Thanks in advance.