Daniel,

This procedure will change the patterns based on a + / - 10,000 condition:

Sub ChangePatterns()

   Dim Cht As Chart
   Dim Srs As Series
   Dim Pts As Points

   Set Cht = ActiveChart
   Set Srs = Cht.SeriesCollection(1)
   Set Pts = Srs.Points

   Cnt = 1

   For Each Pt In Srs.Values

       'Sales greater than 10000
       If Pt > 10000 Then

           Srs.Points(Cnt).Select

           With Selection
               .Fill.Visible = True
               .Fill.Patterned Pattern:=msoPatternWideUpwardDiagonal
               .Fill.ForeColor.SchemeColor = 42
               .Fill.BackColor.SchemeColor = 34
           End With

           'Sales less than or equal to 10000
       ElseIf Pt <= 10000 Then

           Srs.Points(Cnt).Select

           With Selection
               .Fill.Visible = True
               .Fill.Patterned Pattern:=msoPatternLightHorizontal
               .Fill.ForeColor.SchemeColor = 45
               .Fill.BackColor.SchemeColor = 28
           End With

       End If

       Cnt = Cnt + 1

   Next Pt

   ActiveChart.Deselect

End Sub

I may not be understanding what your wanting.  Hopefully this helps.