set cursor in table control field

I have developed module using table control have done validation for one field on Enter key press.In change mode if user changes value in table control field and presses Enter key then system is showing Error message on status bar and table control gets gray out.

if user again hits Enter key then this error message clears and Table control is in Edit mode.

Here I wan that Cursor should go to same filed from which error message occurred.

I have written Get Cursor In PAI event and Set Cursor in PBO after Loop at table control. I tried Set cursor within Lop at Table control in PBO.

But cursor is not coming on that field of table control.

I have written set cursor as below:

Set Cursor Field itab-fieldname Line lineno Offset offsetval.

Here itab is internal table assigned to table control.

Please let me know why cursor is not setting on particular field on table control.