Not for the Clip+, no.
These devices do not #define HAVE_HOTKEY, so no, I'm sorry.
I cannot tell you for what reason this device has the hotkey feature disabled, but I assure you there probably is one, and the reason probably still holds true. Off the top of my head, I seem to recall that the Clip family uses the hotkey key combination to make up for the lack of a hardware lock, but I may be imagining this and it requires a little more digging than I'm prepared to do at 4am.
Anyway, without getting into how and why, the answer (at least right now) is no, sorry. This can't be done to my knowledge.
[Saint]