sounds like you have three tables, two relationships:
Meetings::_pkMeetingID = Agenda::_fkMeetingID
would seem the crucial relationship here and the two meetingID fields would have the value '4' in your example. Make sense so far?
If so, there are several approaches possible, here's one:
Define this calculation field to have items that will number from 01 to 99:
_fkMeetingID &"." & Right ( "0" & Get ( RecordNumber) )
Select the storage option that makes this an unstored calculation.
This should produce the values you want and update to become different numbers if you delete or re-order the items in your portal.
Thank you, I thought it would be a calculation. I don't want any of the other items renumbered though if one of the items is deleted...
I will give this a go.
Then you'll need to use a different method as this system pretty much requires that.
_fkMeetingID &"." & Right ( "0" & ItemNumber )
where ItemNumber auto-enters this:
Max ( AgendaSamemeeting::ItemNumber ) + 1
This requires adding a new occurrence of Agenda, naming it AgendaSameMeeting and linking it by _fkMeetingID before you define this calculation.