Forums / Cotonti / Extensions / Support / Sidepanel plugin always redirects to itself at login

If I correctly understand what your goal is, I don't think you need a plugin for this.

Simply code it as explained in the documentation on their website.

If you want to use a seperate TPL for it you could include it with: {FILE "{PHP.cfg.themes_dir}/{PHP.usr.theme}/tpl/foobar.tpl"}