Zero,
Here's another alternative ...
1. Load the style you want
2. Mute the instrument/track that you don't want.
3. Save the created style as a new style. The muted track will not be saved to the style.

You should then be able to find the style under the category called "Other styles" once the style list has been rebuilt.
I've just test run this with a Realstyle and it seems to work fine.
Regards,
Noel