Tim,
To provide a dropdown of only those dates that are related to the selected case, you need to set the RowSource for Combo96. The way to do this would be to put the following before your "Me.Combo96.Requery"
Me.Combo96.RowSource = "Select fieldlist from table WHERE [CaseNoteNo] = " & Me.Combo74.Columns(0)
Whether or not you use a subform depends on your application. It appears you're having the users select a case number to potentially view or edit information that occurred on a specific date. I'm thinking the subform is probably the way to go. But if you want the subform to display data for a specific date instead of all dates, you probably need to include this date select functionality. Then your subform will be linked to both the case number and the selected date.
Randall J Weers
Membership Vice President
Pacific NorthWest Access Developers Group
http://www.pnwadg.org