It sounds like you are saying that VoxCommando and XBMC are running on the same machine. If that is the case it allows us to do a bit more using the sendkeys or inputkeys actions for keyboard emulation.
With input keys you can emulate pressing shift-J (for example) which would allow you to jump to the profile that starts with the letter J.
If you are not able to use keyboard emulation (because XBMC is running on a remote machine), you can still send keypresses to XBMC, but you can't do shift-Letter, so you would need to send "home" and then right-right-right, or down, down, down to get to the 4th profile. The direction will depend on the skin you are using. Then you can send "enter" to select the profile.
If you then need to enter a password, this will be an additional challenge. Again, this will be easier if you are running VoxCommando on the same computer as XBMC. Having a voice command for your password brings up a certain question about security though, since anyone with access to your machine will be able to see the passwords in the VoxCommando editor, unless you are to going to require the user to say the letters of the password one by one, which is not much fun. At this point you would rather get up and use a keyboard I think.
If your different profiles in XBMC use different databases, this is going to create additional complications for you when you want to generate payloadXML files used to request content. In the past I have only played with profiles a little bit in XBMC. I found them cumbersome and since I don't really need them I gave up pretty quickly. Adding in the complications associated with using MySQL and I must say that I don't really know enough about it to be of much help, but I suspect that it will be challenging to say the least.
