Phil:

This may not be a good idea because you cannot force the grid to display the first calibration record for each visible tool at all times (e.g. it may display the last two calibrations for one tool and the first 4 calibrations for the second tool). If you mean to display the tool number in the first visible of the grid at all times, then I don't think it can be done because grid's rows are not "aware" of the information displayed by the other rows. This tricks work in the Report engine because records are actually scanned one at the time and thus information about the previous record is known.

Have you thought about moving the tool outside the grid and use the grid to display only the calibrations pertaining to the tool?

Hope this helps,
Daniel