So you don't have a phrase called "your_control_panel" already? There should be one.
Anyway, as a test, what happens if you just put the text in there like:
HTML Code:
<li><a href="usercp.php{vb:raw session.sessionurl_q}">Settings</a></li>
ETA: also, when you created the phrase, what Phrase Type did you choose? The existing your_control_panel has type "User Tools (global)".