Maybe this sample helps. I think that you can't edit the Tables fields
directly, but must use Parameters that come with CalculateField.

void __fastcall TFMyyk::QMyykDCalculateField(TIB_Statement *Sender, TIB_Row
*ARow, TIB_Column *AField)
{
if(AField->FieldName=="YHIK")
{
AField->AsString=QCalc->FieldByName("Yhik")->AsString;
}
}

Riho-Rene Ellermaa
senior programmer
Hansabank