Open Doc Using XPage

I would like to use the @Command([ViewSwitchForm]) to switch from a Notes form to an XPage in the client, with the same document loaded. The drop-down does not list XPages, only forms.

Is this possible or am I going about this in the wrong way? Maybe I should be using Javascript?

Subject: Switch to XPage

OK, here’s a simpler question - how do you open an XPage in the client?