Howdy all.  I was searching the net trying to find an easy way to insert an image into Excel when I came accross this VBA Code: http://www.exceltip.com/general-topics-in-vba/insert-pictures-using-vba-in-microsoft-excel.html.  I took a few minutes to translate it to AU3 and was pleased to see it actually worked.  I thought I would share it in case anyone needed something like it. 
#include <Excel.au3>
#include <Array.au3>; for expansion to do many pics from an array
$oExcel = _ExcelBookNew()
$path = @ScriptDir&"\[YOUR IMAGE NAME]"
$targetRange=$oExcel.ActiveSheet.Range("B5:D10")
Func _TestInsertPictureInRange()
	_InsertPictureInRange($path, $targetRange)
EndFunc
_TestInsertPictureInRange()
func _InsertPictureInRange($path, $targetRange)
; inserts a picture and resizes it to fit the TargetCells range
Dim $p, $t, $l, $w, $h
    ; import picture
    $p = $oExcel.ActiveSheet.Pictures.Insert($path)
    ; determine positions
    With $targetRange
        $t = .Top
        $l = .Left
        $w = .Offset(0, .Columns.Count).Left - .Left
        $h = .Offset(.Rows.Count, 0).Top - .Top
    EndWith
    ; position picture
    With $p
        .Top = $t
        .Left = $l
        .Width = $w
        .Height = $h
    EndWith
    $p = "Nothing"
EndFunc
Enjoy.