If you give all the input dropdowns the title 'Input', you could use:
Code:
Private Sub Document_ContentControlOnExit(ByVal ContentControl As ContentControl, Cancel As Boolean)
Dim StrOutput As String, CtrlID As String
If ContentControl.Type <> wdContentControlDropdownList Then Exit Sub
For Each ContentControl In ContentControls
If ContentControl.Type = wdContentControlDropdownList Then
If ContentControl.Title = "Input" Then
If ContentControl.Range.Text <> ContentControl.PlaceholderText Then
StrOutput = StrOutput & ContentControl.Range.Text & "+"
Else
StrOutput = StrOutput & "N/A" & "+"
End If
End If
End If
If ContentControl.Title = "Output" Then CtrlID = ContentControl.ID
Next
StrOutput = Left(StrOutput, Len(StrOutput) - 1)
ContentControls(CtrlID).Range.Text = StrOutput
End Sub
If they all have different titles, you'll need to add a series of OR tests to the 'If ContentControl.Title = "Input" Then' line.