Have ComboBox Appear On Cell Selection & Double Click

I am looking for assisitance in combining the functionality of two seperate combo box code sets. The first combo box code set allows the combo box to automaticially appear when a user Clicks on a cell that contains a data validation list. The second set of code will have a combo box appear when a user Double-clicks on a cell that contains a data validation list. And the code allows for Named Ranges on a seperate worksheet.
I would like to have the functionality of having the combo box to appear when a user Clicks on a cell and not having to Double-click. Also, I would like to have the option to use Named Ranges on a seperate worksheet ("Validation Lists").

Private Sub Worksheet_SelectionChange(ByVal Target As Range)
Dim str As String
Dim cboTemp As OLEObject
Dim ws As Worksheet
Set ws = ActiveSheet
On Error Goto errHandler
If Target.Count > 1 Then Goto exitHandler
Set cboTemp = ws.OLEObjects("TempCombo")
On Error Resume Next
If cboTemp.Visible = True Then
With cboTemp
.Top = 10
.Left = 10
.ListFillRange = ""
.LinkedCell = ""
.Visible = False
.Value = ""
End With
End If................