Simply select your drawing, or any part of it and copy it to clipboard. For this, you can use Ctrl+c in versions 18.7 or earlier or select Copy as from Edit menu or Ctrl+D and then MarvinOLE format in 18.8 or higher.
The selection can be pasted into any OLE-capable application, like Microsoft Office Family (if OLE support is enabled).
This feature also works in a reversed way: select an embedded Marvin OLE document from your Excel Sheet or Word Document, copy to the clipboard (Ctrl+c), then use the paste function (Ctrl+v) at your MarvinSketch to retrieve the structure.
IF OLE copy does not work for you, please check the followings:
Make sure JChem_NET_API is installed on your machine. (If you open Add/Remove Programs section in Control Panel, you can check easily whether the required component is on the list.
Open the C:\Program Files\ChemAxon\Shared\MarvinOLE folder to check whether MarvinOLEserver.exe is there.
Check whether the OLE copy option is enabled in the Copy As... dialog in the Edit menu of Marvin. If not, the OLE server is not registered. Uninstalling and reinstalling JChem_NET_API can help in this case.