I wish to add a command on right click menu in explorer that opens current directory with cygwin.

For same I have successfully added these registries:

[HKEY_CURRENT_USER\software\classes\directory\shell\cygwin]
@="c:\\cygwin\\bin\\bash.exe --login -i -c \"cd '%1'; bash\""

[HKEY_CURRENT_USER\software\classes\drive\shell\cygwin]
@="c:\\cygwin\\bin\\bash.exe --login -i -c \"cd '%1'; bash\""

but this adds the command only when on some folder or drive. I want generic right click on explorer, on which, search gives me this registry to edit:

[HKEY_CLASSES_ROOT\Directory\Background\shell\cygwin]
@="c:\\cygwin\\bin\\bash.exe --login -i -c \"cd '%1'; bash\""

My problem lies with the value of the key, which doesnt work on %1 but on some static value like /cygdrive/c

Could someone please tell me the proper way to pass current directory to the command, also please refer me some basic and advanced pages for same.

Thank you.