ListFillRange Property
Returns or sets the worksheet range used to fill the specified list box. Setting this property destroys any existing list in the list box. Read/write String.
Remarks
Microsoft Excel reads the contents of every cell in the range and inserts the cell values into the list box. The list tracks changes in the range’s cells.
If the list in the list box was created with the AddItem method, this property returns an empty string ("").
Example
This example adds a list box to worksheet one and sets the fill range for the list box.
With Worksheets(1)
Set lb = .Shapes.AddFormControl(xlListBox, 100, 10, 100, 100)
lb.ControlFormat.ListFillRange = "A1:A10"
End With