First if its a drum kit such as the XP 30 808 kit or any MIDI drum kit it based on one note pitch equals one drum type. C = kick D = tom and so on. So if you want to raise the pitch of the 808 kick for example you can't by going to a higher pitch note. You will change only the type.
What was offered above are ways for you to make your own sounds. You could see about sound fonts. Or you could buy a kit with ethnic drums. East Indian drums have some variable pitch drums. An 808 kit is modeled after an acoustic kit with limited pitch variability.