Very dynamic field-symbols

In a SAP customer function you sometimes want to refer to data from the calling program (if this data is not part...

of the function interface). A function group has its own global data area.

Using the following syntax for field-symbols it is possible to do just this. 
=> calling program is SAPMV45A
=> Field we want to refer to is YVBAK-BSTNK

This same logic also works for external subroutines but of course not for SUBMIT.   
		
		Code: FIELDNAME = 
'(SAPMV45A)YVBAK-BSTNK'.  
ASSIGN (FIELDNAME) TO 
 
  .