As the boys have said earlier, the process is not simple.

This example is as simple as I could make it, it returns the values in column "A" of the active worksheet in workbook "c:\temp\demo.xls"

This demo assumes that the first empty cell is the end of the list (otherwise *all* possible cells in column A are returned).

Code:
Break ON
 
$sMyDocument="C:\temp\demo.xls"
 
; Create Excel application
$oExcel=CreateObject("Excel.Application")
 
; Uncomment the next line to make it visible
; $oExcel.Visible = 1
 
; Load the demo document
$oWorkbook=$oExcel.Workbooks.Open($sMyDocument)
 
; Get the active worksheet
$oWorksheet=$oWorkbook.ActiveSheet
 
; Iterate the cells in column A, stopping on the first blank cell
For Each $oCell in $oWorksheet.Columns("A:A").Cells
	$iCounter=$iCounter+1
	$sText=$oCell.Text
	If $sText="" Goto "CellLoopDone" EndIf
	$iCounter " " $sText ?	
Next
:CellLoopDone
 
; Clean up
$oExcel.Quit()
$oExcel=0
 
Exit 0


If anyone can think of a nicer way to break out of the collection iteration I'd be interested.