I have decided that the only way to edit the alias list is to go directly to the pgp file and then reinitialise it in autocad.  I have all the necessary permissions, and the alias edit sometimes works, but at other times I get the following error:

And reinit doesn't always work, either.  I changed the list so that D is Dtext, and DD is Dimstyle.  But autocad will not recognise DD:

And then I changed -B to be Block, and B to be -Block, but it didn't work.  When I went into the actual pgp file, it had put a series of ;;; in front of both B and -B, and hadn't changed them, either.  Can anyone tell me what I'm doing wrong?