i'm not sure but maybe this helps...
SELECT TblLine.LineID, TblLine.LineType, TblLine.LineDim, TblLine.LineShape,
FctConvertInch([LineDim],[LineShape]) AS Conv
FROM TblLine
GROUP BY TblLine.LineID, TblLine.LineType, TblLine.LineDim, TblLine.LineShape;
i think you can't use an...