How can I remove a blendShape target in overlapped case?

[hyungeun-kim]

I have 2 cube, (pCube1 and pCube2)
and I create a blendShape from pCube2 to pCube1, so I get a blendShape1
after that I add blendShape target pCube2 to blendShape1 again.
So it means that in blendShape1, I have 2 weights that result in same way.
In that case, how can I remove just a weight?
I try to use like that "blendShape -e -rm -t pCube1 2 pCube2 1", but it comes out removing all of them.