Transform XSD to another XSD

I'm going to have a master schema with around 100 elements, some simple, some complex. Numerous customers will use only pieces of the schema that are relavent to their process. Is there some way I can generate/extract/etc. the custom schemas out of the master without having to simply do a copy/paste job? We thought of just providing the whole thing to customers, but in many cases all they are five or six elements, so giving them a schema with 100 seems a bad thing.

I'm sure others have run into this...what have you done?

Thanks!