Stretch something along another line

Hi,

I ve got a question:

I want to stretch a part of a picture to a different shaped line. Say, I've got a C-shaped pic, but I want to disfigure it to a S-shaped pic of different scale. Is that possible?

I ask because I'm working on difficult a 3-d model texture, and the arms and legs still have seams I can't get rid of.

Yours,
Lessa