Setting ChartData according to the index number in a combobox

[RawlinsCross]

This should be fairly straight forward but I'm missing something:

I have a combobox with 13 items that reference a different column of data. I'm trying to tell excel to graph based on the index value of that combobox. It's working but only with the first selection (i.e. index = 0). here's the portion of the code in question.

If ChartIndex1 = 0 Then
Set ChartData1 = Worksheets("212-R365").Range("F" & r.Row & ":F" & rn1)
ElseIf ChartIndex1 = 1 Then
Set ChartData1 = Worksheets("212-R365").Range("H" & r.Row & ":H" & rn1)
ElseIf ChartIndex1 = 2 Then
Set ChartData1 = Worksheets("212-R365").Range("AK" & r.Row & ":AK" & rn1)
ElseIf ChartIndex1 = 3 Then
Set ChartData1 = Worksheets("212-R365").Range("EA" & r.Row & ":EA" & rn1)
ElseIf ChartIndex1 = 4 Then
Set ChartData1 = Worksheets("212-R365").Range("U" & r.Row & ":U" & rn1)
ElseIf ChartIndex1 = 5 Then
Set ChartData1 = Worksheets("212-R365").Range("AL" & r.Row & ":AL" & rn1)
ElseIf ChartIndex1 = 6 Then
Set ChartData1 = Worksheets("212-R365").Range("P" & r.Row & ":P" & rn1)
ElseIf ChartIndex1 = 7 Then
Set ChartData1 = Worksheets("212-R365").Range("AM" & r.Row & ":AM" & rn1)
ElseIf ChartIndex1 = 8 Then
Set ChartData1 = Worksheets("212-R365").Range("Q" & r.Row & ":Q" & rn1)
ElseIf ChartIndex1 = 9 Then
Set ChartData1 = Worksheets("212-R365").Range("R" & r.Row & ":R" & rn1)
ElseIf ChartIndex1 = 10 Then
Set ChartData1 = Worksheets("212-R365").Range("D" & r.Row & ":D" & rn1)
ElseIf ChartIndex1 = 11 Then
Set ChartData1 = Worksheets("212-R365").Range("T" & r.Row & ":T" & rn1)
ElseIf ChartIndex1 = 12 Then
Set ChartData1 = Worksheets("212-R365").Range("S" & r.Row & ":S" & rn1)
End If

 

[Worf]

Something like this:

Private Sub Worksheet_Change(ByVal Target As Range)
Dim chartdata1 As Range, rn1%, ci%, r As Range, ws As Worksheet, ra
ra = Array("f", "h", "ak", "ea", "u", "al", "p", "am", "q", "r", "d", "t", "s")
Set ws = Sheets("212-R365")
Set r = [3:3]
rn1 = 5
ci = Me.ComboBox1.ListIndex + 1
Set chartdata1 = ws.Range(ra(ci) & r.Row & ":" & ra(ci) & rn1)
MsgBox chartdata1.Address
End Sub