The latest v5 version of the MS Excel VBO object has actions called select and copy - these can be used to select a range of cells and copy them to clipboard. If these are usable for you then you would not need to use global keys to copy from Excel.
If the Select/Copy actions do not work for you, I do know of some clients that have successfully copied data out of Excel using surface automation, so It should be possible. Maybe contact your Blue Prism mentor for help.