You need a modelling program.

Hexagon
3D Max
Carrera
Wings3D

Or any number of others. Hexagon was on sale at Daz, not sure if it still is.  And there are some free modelling programs. Not sure if Carrera is one or not.

Be warned that it's not easy and takes lots of practice and has a steep learning curve. So don't go into it thinking that you'll be pumping out clothing the day you get a program.

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi