Adding Larger Icon On Excel 2007 Ribbon Button

Question

I've got an Excel 2007 VBA script that adds a button to the ribbon, but unfortunately the icon is tiny. I tried several different FaceId's, but they all seemed to add tiny icon buttons. Is there a way to load in some of the newer 2007 size icons?

Here is a snippet of the code that I've got loaded in ThisWorkbook:

Set NewButton = NewToolbar.Controls.Add(Type:=msoControlButton)
With NewButton
     .FaceId = 752
    .TooltipText = "Convert XLS Files to CSVs"
    .OnAction = "XLSTOCSV"

Thanks for any insights about increasing the size of the icon.