I made that post Timo pointed to and can add a little more information to it:
Back then I was only doing HTML skinning and was relying on DNN to parse the files and create the ASCX upon upload. The stuff I wrote in that post was for HTML skins. Now I tend to use HTML just for the first skin upload and then I work on the ASCX files directly on the server from there on in.
Here is an example of the resulting code that you need to see in the ASCX file after parsing the HTML and XML files. If you only use ASCX to create your skins or you are modifying an existing ASCX skin, then you only need your version of this code. Note that the DNN Blue skin and container folders contain both the HTML/XML files and the parsed ASCX files. If you only modify the HTML/XML files then you will have to re-parse them on the skins page to see the change. If however you only modify the ASCX files then you can see the changes immediately upon page refresh. In this case, beware that you will lose your ASCX changes if you accidentally re-parse the skin using the original HTML files. It can therefore be a good idea to remove or rename the HTML files in the skin folder in this case.
This example I've given forces the default DNN Blue skin to use the "Text Header - Color Background" container in the "RightPane".
This is your "RightPane" table cell:
<div runat="server" id="RightPane" containertype="G" containername="DNN-Blue" containersrc="Text Header - Color Background.ascx"></div>
Note that by specifiying "G", it is using the "Global" or "Host" skin and container. To make this work on a skin uploaded as "Admin" or "Local", insert "L" instead of "G".
That should either help or further confuse things :)
P.s. I'm not home testing this, but off the top of my head, it is correct.
Regards,
Rob