Help with auto selection

I need help to make the ComboBox9 is filled with the ComboBox8 information complement.

For example, if in ComboBox8 in column A2 is the first name "Mike", and it is selected, in ComboBox9 in the same row and corresponding column, which would be B2, is the last name "Jones", be filled in ComboBox9

Private Sub ComboBox9_Change()


End Sub

Private Sub UserForm_Activate()

'ComboBox8
Dim totLIN2 As Long, LIN2 As Long
totLIN2 = Plan2.Range("c" & Rows.Count).End(xlUp).Row
ComboBox8.Clear
For LIN2 = 1 To totLIN2
ComboBox8.AddItem Plan2.Cells(LIN2, 3)
Next

'ComboBox9

'HELP???

End Sub