Especially for Guest (G-Exempt) accounts which support multiple
concurrent logons - the 'curxtrn' value stored in the user's record
may not match the external program that was actually last executed
on the node in question, so use the .aux property value (from
node.dab) as is done in the C++ code (e.g. printnodedat()). This insures
that the node_status() output here matches the C/C++ code output
(e.g. when logging on the terminal server).

Still support the 'code-based' external program name look-up since
that usage is relied upon by other modules, but when a number is
passed, use the number to find the right external progarm name
(and we need to subtract one, since aux is a 1-based number).

I've looked at this problem a couple of times before and not sure why
I didn't see the solution. <shrug>