Attached Link: ShaderSpider Bonus Pack

Partial shaders (FX6 files) can cover the role of partial MAT poses, but require ShaderSpider to save and load them. There are some examples of partial shaders I've created using ShaderSpider in the above link. Note that you cannot translate a MAT pose into a partial shader as of this writing. The only other solution that I'm aware of is to do as nruddock says and code your modification into a Python script.