I want to add custom context menu options for certain file extensions (like .zip-files) for a program I'm developing. However on many (but not all) PCs my software is going to be installed on 7-Zip is installed as well and therefore [HKEY_CLASSES_ROOT.zip] is referring to [HKEY_CLASSES_ROOT\7-Zip.zip] in the registry.
As I don't want to tamper with the original 7-Zip installation I just want to add my context menu options on top. However entries in [HKEY_CLASSES_ROOT.zip\shell] are without effect and I don't know how I could link [HKEY_CLASSES_ROOT.zip] to [HKEY_CLASSES_ROOT\MyApp.zip] because the default value of [HKEY_CLASSES_ROOT.zip] is already being used by 7-Zip.
Any help would be greatly appreciated :)