terkin_vv, потестируйте такой код
Dim DB As DAO.Database, RSD As DAO.Recordset, RSM As DAO.Recordset, fld As DAO.Field
Dim sq$, sf$
Set DB = CurrentDb
sq = "SELECT * FROM Дела ORDER BY УД, [Дата ВУД], Код"
Set RSD = DB.OpenRecordset(sq)
sq = "SELECT T1.* FROM Дела As T1 " & _
"WHERE T1.Код=(SELECT Min(T2.Код) FROM Дела As T2 " & _
"WHERE T2.УД=T1.УД And T2.[Дата ВУД]=T1.[Дата ВУД]) " & _
"ORDER BY T1.УД, T1.[Дата ВУД]"
Set RSM = DB.OpenRecordset(sq)
Do Until RSM.EOF Or RSD.EOF
If RSM!Код = RSD!Код Then
RSD.MoveNext
ElseIf RSM!УД = RSD!УД And RSD![Дата ВУД] = RSM![Дата ВУД] Then
RSM.Edit
For Each fld In RSM.Fields
sf = fld.Name
If Len(RSM(sf) & "") = 0 Then RSM(sf) = RSD(sf)
Next
RSM.Update
RSD.Delete
RSD.MoveNext
Else
RSM.MoveNext
End If
Loop
Set fld = Nothing: RSD.Close: RSM.Close
Set RSD = Nothing: Set RSM = Nothing: Set DB = Nothing