Library /sys$common/syshlp/lse$menu.hlb SET_DIRECTORY_DEFAULT  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  Syntax:  SET DIRECTORY DEFAULT directory_spec

  Changes your default device and directory specifications.

  This command applies the new default device and directory names to
  all subesequent file specifications that do not explicitly include a
  device or directory name.  The default set in an LSE editing session
  remains in effect after you terminate the LSE session.