SkinClip is the analogue of sub sequence in jPCT's Animation class. It's for whole skeleton, JointChannel is only for a joint in skeleton.
I can expose the internal data in JointChannel, but may not be trivial to split a channel's animation into shorter ones.
It's a bit weird EasyOgreExporter doesnt support multiple animations, it's written 'multiple Skeleton Animations' in their web page. Anyway, if that is the case, I would suggest, export each animation into a different file, and merge them with Bones, so you will end up with separate animations. merging can be done either with scripts (multiple input files) or programatically with AnimatedGroup.mergeAnimations(..) method.