Count or Detect Graphic Objects in an Excel Spreadsheet Opened in Access?

Hi Gurus,
I have an application that opens Excel Spreadsheets in Access and
extracts information to be placed into tables. One thing I need to do
is detect if the spreadsheet contains any drawing objects such as
lines, boxes, bitmaps, etc.
I tried

Dim g As Integer
Dim dG As Graphic
Dim xlWS As Excel.Worksheet

Set xlWS = xlIW.Worksheets(strWSheet)

g = 0
For Each dG In xlWS
g = g + 1
Next dG

But it is telling me that the object does not support that property or
method. Any suggestions? I don't need any elaborate information, just
if they exist or not.
Thank You!
-plh