How to make a logic script ?

Hi all !

I would like to make a simple thing : make a SUM of 4 accounts by a LogicScript.

I make this one, called CALC_EFF.LGF, which I included in my DEFAULT.LGF (*INCLUDE CALC_EFF.LGF)

*XDIM_MEMBERSET COSTELEMENT =G101,G102,G120,G122

*WHEN COSTELEMENT

*IS G101

*REC( EXPRESSION =%VALUE% , COSTELEMENT=EFF_DIRECT)

*IS G102

*REC( EXPRESSION =%VALUE% , COSTELEMENT=EFF_DIRECT)

*IS G120

*REC( EXPRESSION =%VALUE% , COSTELEMENT=EFF_DIRECT)

*IS G122

*REC( EXPRESSION =%VALUE% , COSTELEMENT=EFF_DIRECT)

*ENDWHEN

Is there some mistake in my code ?!

Is it possible to make it buy a Business Rules ?