Forum OpenACS Q&A: error with \copy command

I am trying to copy the data into the pgsql using tcl.

set tcopy " \\copy tmp_reb_user_group from tmp.txt using delimiters \"|\" "

set selection [ns_db exec $db $tcopy]

However, there were error messages from the log file

14/Feb/2003:03:35:08][19272.11270][-conn3-] Error: dbinit:

error(localhost::tanh,ERROR:  parser: parse error at or near "\"
): ' \copy tmp_reb_user_group from tmp.txt using delimiters "|" '

I think it is because of "\" character. Although, I have try to add more \ but it doesn't work.

Could you please point out my mistake. Thank you very much

copy tmp_reb_user_group from 'tmp.txt' using delimiter '|'

However, when I try to test with psql shell, I can not use the copy command since It display error message

You must have Postgres superuser privilege to do a COPY directly to or from a file.  Anyone can COPY to stdout or from stdin.  Psql's \copy command also works for anyone.
that why I try to use \copy in TCL.

Note the following command work fine with psql shell
--
\copy tmp_reb_user_group from tmp.txt using delimiters "|"
--

Some one suggest me to use "exec "
to exec the psql command. I have try but it doesn't work
like

psql \copy tmp_reb_user_group from tmp.txt using delimiters "|"

I think it is the problem that I pass the command incorrectly to psql shell . Could you please point out my mistake?
Thank you very much