Modified to Created

[Phil Harvey]

If you drag the "Test" folder onto the Terminal window it should type the full path of that folder for you.  If you do this, then you shouldn't get the "File not found" error (which I presume is because the path wasn't entered properly somehow).

When I drag an "untitled folder" folder from my Desktop for example, I get this entered in the Terminal window (OS X 10.10.5):

  /Users/phil/Desktop/untitled\ folder

- Phil

[findlay70]

OK thanks Phil - I found the issue. I was dragging it to the terminal icon on the tray. Instead, I minimized the finder and pulled the folder across into an open terminal window and it worked... thanks for the pointer...
Andy

[findlay70]

So your final command would look like this:
exiftool '-DateTimeOriginal<FileModifyDate' -r -overwrite_original /Users/Andy/Documents/Test

OK, so I got this working - my path was incorrect.
But the issue now is that the the file/s have today's date which is not what I want. I want to preserve the capture/create date file, not overwrite the original.

I'll play around with it more to see what I can figure out.. thx

[Phil Harvey]

You should add -P to the command to preserve the original FileModifyDate as I mentioned.

- Phil