COPY with a variable path - Mailing list pgsql-general

I want to execute the following COPY command in a stored procedure,
however, I need to pass the path to the file as an input parameter.
Substituting the input parameter for the literal path does not work and
neither does using PREPARE/EXECUTE. How can I pass the file path as a
parameter?

  copy contact.palm_import from 'c:/_junk/palm.csv'
  with delimiter as ','
  null as ''
  csv quote as '"';

Thanks,

Bill