how to cycle b/w hex and dec in calculator using keyboard shortcut

Hi

I have searched all over the place, could not find the keyboard shortcuts to cycle b/w hex and dec on the programmers calculator.

In Windows I used the function keys(F5,F6,etc..) to change between input mode selector(Bin, Hex, Dec, etc) , in the Mac OS X calculator I couldn't find those shortcuts!!

I am looking for keyboard shortcuts, not how and where to click using mouse.

Thanks,

-Tim.