I didn't initiate this thread, but have received many responses.   This is sort of taking a diffent tack.  Jeff Vance responded to the original question the concept of "entry points" as a form of subroutine.  This is perhaps the most direct solution I've seen thus far.   It requires rather complex script writing but examples are available.   
Here are some comments on some of the other side comments.

1.    MPE/IX does indeed recognize HFS paths, but the commands become case sensitive.  Is there any way around this?  Otherwise this would essentially nix the idea of moving what already exists from MPE to HFS, but this can be utilized for new command files or commands that require more than 8 charaters.   If there is no way to force upshift, then two copies of the command file can then be put into the HFS directory, one caps & one lower case and hopefully no one will issue the command with only the first letter capped.   

2.   Our current version of MPEX from VESOFT does not recognize HFS paths.   Most of the work done by programmers, managers and operators is done at the MPEX prompt or whithin scripts that invoke MPEX.   

3.   Execute access is all that is required to execute command files.  But, eliminating Read access will also eliminate HELP access.   Many of the command files are heavily commented for the purpose of "HELP".  Also, the system is heavily secured with VESOFT security and access to the system prompt is limited to a handful so I am not concerned about Read access.

4.  I haven't yet tried POSIX scripts.   I'll add to this thread when I do with results.

Thanks to all,

Tom Genute

    -----Original Message-----
    From: VANCE,JEFF (HP-Cupertino,ex1) <[log in to unmask]>
    To: 'Tom Genute' <[log in to unmask]>; [log in to unmask] <[log in to unmask]>
    Date: Tuesday, March 27, 2001 4:00 PM
    Subject: RE: [HP3000-L] Subroutines on UDCs?
    
    
    ...
    > Unlike UDC'S command files do not load on logon and do not
    > require a SETCATALOG.  Therefore they require less logon overhead per
    > session and the commands are usually more easily modified, 
    > debugged, etc. The downsides are that the command name is limited to 
    > MPE file naming conventions (8 characters)
    
    This is no longer true after MPE 5.5 exp [3,4,5]?  There is an article
    on Jazz and it is described in the official Communicator for 5.5.
    Cmmand files can reside anywhere in the HFS, and elements in the HPPATH
    variable can be HFS named directories.
    
    regards,
    Jeff Vance, CSY