Experiencing issues / problems selecting OLE (eg Excel) Objects within a drawing file, the below information might just help resolve such issues / problems....
Autodesk Knowledge Base:
ID: TS64541 - Unable to select inserted OLE object to remove or edit it
ID: TS47880 - Cannot select OLE objects in a drawing
ID: TS45002 - OLE objects are selected in all layouts
Adding a disclaimer to a drawing.
OLE Object will not allow selection
Unable to select inserted Word file