Checked it. We cannot save a CAT drawing as a single sheet. you can copy and paste it into another drawing file. However you can save a CAT Drawing as individual sheets as a pdf. For this you have to change the settings in the tools.options..compatibility...graphics formats...pdf...save multiple sheets ( on or off ).
Hope it helps. All the best.
You can do this manually by Cut/Paste or script the Cut/Paste.
To make the macro:
Use the macro recorder to record yourself cutting and pasting twice.
It gives you most of the code you'll need to save each sheet as its own drawing.
Then just add a loop through go through each sheet in the original drawing.