You need to look at other skin files. Mine is listed below but is somewhat customized. Essentially you need the A/ line which tells where you want the Dashcommand window to open. X,y,width and length. You will also need whatever buttons are needed on that screen. I always start with a skin file that has on it what most of what I want and change the skinfile name so that it opens for that program. The Bottom Row off stuff is for the picture files of the bottom buttons. The inc buttons.txt, are where my button info is, where most people have the button info in every skin file. The B/ line is to take me back to the main menu screen, and the A/ line as I said tells where on the screen to open the application window.
Here is my Dashcommand Skin file:
/, B, x, y, w, h, Command;COMMANDCODES, Tooltip
/, A, x, y, w, h, color R;RGB, G, B