Hardware :: Keyboard Fn Modifier Key (not F1 - F12)

Using: Ubuntu Lucid Lynx (Gnome).
I have a physical disability which makes pressing the <Ctrl><Alt> key combination very hard, but it would be nice to have that key combination available to me for keyboard shortcuts. I've never got on with 'Sticky Keys' and don't want to use that as a solution, it takes me so long that it is self-defeating as a shortcut key combination. I use a reduced size keyboard, a Cherry ML4100 (image below), which has a 'Fn' key between the left <Ctrl> and <Alt> keys, this 'Fn' key when pressed in conjunction with F1 or F2 will simulate a F11/F12 key press (see image), it also allows the use of a 'num pad' with the u,i,o,p, etc. keys to the right of the centre of the keyboard but which I never use.

In System -> Preferences -> Keyboard Shortcuts I can not currently use the 'Fn' key at all, it is totally ignored, the system just does not recognize it. Eg. If I press <Fn><A> only 'A' is recognized. What I'd like to do is somehow map the 'Fn' key so that when pressed at the same time as <Ctrl> it simulates a <Ctrl><Alt> key press, while still leaving 'Fn' to work as usual generating F11/F12 key presses when F1/F2 is pressed with it. Alternatively if I could set up the 'Fn' key to work as a shortcut with any other key, EG. <Fn><LeftArrow> to switch to the left workspace, and then map F11 and F12 to another key combination - in fact this second solution would be preferable.

However the xev utility, which I had hoped would provide me with a key mapping code for 'Fn', does not even register when 'Fn' is pressed on its own, but when 'Fn' is pressed with F1 it gives what I suppose is the the F11 key code (it is a different code to what is shown when F1 is pressed on its own). I am beginning to suspect that what I am trying to do is not possible. My disability means that using keyboard shortcuts is a really good way of my doing things, much faster than the mouse, so I'd like a lot set up, and I mean far more than most people would ever use, including starting a dozen or so regularly used apps, I'm running out of what I can do with <Ctrl><Shift>, so really need to simulate <Ctrl><Alt> or have the 'Fn' key active when setting my Keyboard Shortcuts, EG. <FN><A>.