Subst

SUBST is a command on the DOS, IBM OS/2 and Microsoft Windows operating systems used for substituting paths on physical and logical drives as virtual drives. It is similar to floating drives, a more general concept in operating systems of Digital Research origin, including CP/M-86 4.x, Personal CP/M-86 2.x, Concurrent DOS, Multiuser DOS, System Manager 7, REAL/32, as well as DOS Plus and DR DOS (up to 6.0).