Need more details on what you are trying to do but you can add points based on the question and the value of the combo box. In the AfterUpdate of the combo box, you could do something like:
If Me.Combobox = "YES" thenIf Me.QuestionID = 1 Or Me.QuestionID = 2 then
Me.QuestionPoints = 18
Else
Me.QuestionPoints = 5
End If
Else
Me.QuestionPoints = 0
End If
This assumes you have a table of questions (QuestionID, QuestionText, QuestionPoints) and assumes questions 1 and 2 get the 18 points if Yes is marked.