Hello Edward
thanks for your reply, but i have a doubt
first:
where in my code i must apply "Column.Control.Lostfocus or Column.Control.Interactivechange events"
because i only can make these event on runtime not in design mode.
also i have another code to capture the position of the active column in the grid and hide them with the event before form init:

STORE "" TO clname
FOR EACH myform IN _Screen.forms
IF UPPER(myform.name)="SBO"
WITH myform.Pageframe1.Page1.Cont1.Grid1
FOR i=1 TO .columnCount
IF UPPER(.Columns(i).ControlSource)="BI.EDEBITO"
clname=.Columns(i).name
.RemoveObject(clname)----(a)
exit
ENDIF
NEXT i
EXIT
ENDWITH
ENDIF
NEXT myform

i don´t know if i could use the event AFTERCOLROWCHANGE and in the code position(a), i can make a property for detecting if the value changed in this column, or after your suggestion on the first code i can resolve my problem.

Many thanks for you kindly help
Luis Santos