refn 
	- Dereference ptr-to-number: *(ub<numsize>*)(((ub1*)<ptr>)) + <offset>)
Usage
-------
refn( ptr             <pointer>,
      numsize         <ub8: 1 | 2 | 4 | 8 > default '4',
      offset          <ub8> default '0',
      Action returns: <ub8>)