If you wish to add tracking pixels to all the external pages in your Spawtz installation, you can do so by editing the main "Skin Html" for the site.  The skin html can be edited via the config section:

1) Log in as an administrator

2) Click "Config"

3) Click "Edit Skin Html"

4) The raw html of the site's skin will be displayed to you.  Follow the instructions from the tracking company with regards to placement of the required javascript code within the html.

5) Click "Update Skin File"

Your tracking pixel code will now appear in every external page.