Alternaticelly heres a quick and dirty macro that selects all cells with formulae and formats them White-on-black
Sub HighlightFormulae()
Selection.SpecialCells(xlCellTypeFormulas, 23).Select
With Selection.Font
.ColorIndex = 2
End With
With Selection.Interior...
The only way I think this can be done is to first use a script in AutoCAD to export the image as a metafile or .jpg
then in excel use a VBA cell event to import the image.
Sorry not sraight forward an will require a small amount of both VBA programming and AutoCAD scripting/AutoLISP