>I also tried this:
>

>oExcel.ActiveSheet.Range("K22").Formula = "=SUM(K19;K16;K10;K7)"
>

>And I got this error message:
>"OLE error code:0x800a03ec:Unknown COM status code"
>
>It may have sg. to do with the Hungarian version of Ms Excel?
>I gonna check Naomi's links.
>
>Thanks again,
>Tamas

Try also to use FormulaLocal instead of Formula (suggested in another thread).

Also, though irrelevant, perhaps you need to use cells in the different order, e.g. K7,K10,K16,K19.