First off, sorry I haven't got round to doing the images yet - bad day health-wise.

If you've created the control map in photoshop, you shouldn't need the group tool. Go into the material room, and select the material that covers the body area (skinbody, torso, or whatever it's called). From the diffuse colour node right at the top, disconnect the image map. Reconnect the diffuse colour to a blender node (found under new node -> maths -> blender). Connect the image map into the first input, and make sure the colour is set to white. Set the second colour to whatever shade you want the highlighted area to be (in this case, red). Set the Blending attribute to 1, and it is this third parameter which you connect to your control map.

To confirm what the control map should look like - it should be all black, aprt from the area you want to be highlighted on the figure; this area should be filled in white.Use either the original skin texture as a guide (but be sure to work in layers and save it as a different file name - you don't want to overwrite the original texture!), or find one of the many seamguides dotted around the freestuff here at Renderosity (Snowsultan seems to have worked tirelessly to bring annotated seam guides for every single major character going).

I promise, I will get round to sorting out some images based on this as soon as I can find the concentration and energy to do so - unless someone else can take up that particular baton and help?

jonthecelt