How do I link commandbuttons to combobox selection?

Change the combobox properties:
BoundColumn=0
ColumnCount=1

Add the below to the very top of Module1

Public Product_SKU_Row  As Long
Public Enum Headers
    Spin = 3
    Video = 4
    In_Use = 5
    Photo = 6
    WebCollage = 7
    Reviews = 8
    Article = 9
End Enum

Modify the form's button codes as was done with Start360_Click

calculate the sku row in the worksheet:

Private Sub cboProductSKU_Change()
    Product_SKU_Row = cboProductSKU.Value + 2
End Sub

Private Sub Start360_Click()
    With Cells(Product_SKU_Row, Headers.Spin)
        .Value = IIf(.Value = "", "S", "")
    End With
End Sub

When choosing the column numbers for the cell, type Headers. then choose the header from the dropdown.