How do I program a feature button to dial someone's extension directly? I've worked out how to program a speed dial outside number. "Redial", "Speeddial", feature button, phone number, "Redial". When I try to reprogram a feature button that already has an extension tied to it, when I get past "redial", "Speeddial" and hit the feature button, it starts ringing the extension that is currently programmed.

You are referring to a DSS key. On a Toshiba DK the user cannot program a DSS key. It has to be done in system programming.