Syntax:

RAR ‹command› [ -‹switches› ]  ‹archive›  [ @‹listfiles›... ]
        [ ‹files›... ]  [ ‹path_to_extract\› ]

Please use command a to add files to an archive

Example A:

create or update existing archive myarch, by adding all files
in the current directory

rar a myarch

Example B:

create or update existing archive C:Backupmyarch, by adding all files
in the directory C:Settings and C:Work and in all sub-directories of both
directories. (Switch -r :     Recurse subdirectories)

rar a -r C:\Backupmyarch C:\Settings C:\Work