how to isolate curve deformation to specific layers

I am wanting to deform my arm via curve deformation, though cant figure out how to not deform my t shirt at the same time. I could do this by not grouping my arm and sleeve, though the problem with that is that they move separately when I rotate the shoulder.
Essentially I want to be able to rotate them both with the deformation handle, but want to deform the t shirt and arm separately without either influencing one another (except when I rotate the shoulder I want the arm to follow)

Ideas please?

Screen Shot 2014-09-07 at 4.50.43 pm.png

It might also be useful to mention you can create a kinematic output from your deform to make elements follow without deforming them

http://docs.toonboom.com/help/harmony/#HAR/Stage/018_Deformation/021_H1_Deformation_Toolbar.html?Highlight=kinematic output

Amazing how you can muck round with problems for days, and as soon as you post a question you figure it out…

Didnt realise you could create a chain of curve deformers and that has solved my problem