Execute a string of command in sql'script

Hi all,
I'm using PostgreSQL 7.0.2 on RedHat 6.0.

I compose a SQL command string with function below :


CREATE FUNCTION bdrm_copy(text, text) RETURNS text AS '

 DECLARE
  baseact  ALIAS FOR $1;
  namefich ALIAS FOR $2;
  path0 TEXT;
  path1 TEXT;
  path2 TEXT;
  path3 TEXT;
 BEGIN
  SELECT INTO path0 CAST(ig_tempo AS TEXT)
  FROM ti_bdrm
  WHERE ig_base = baseact;
  path0  := trim(path0) || trim(namefich);
  path1 := ''COPY ttx_window7 TO \'\''';
  path2 := path1 || path0;
  path3 := ''\'\''';
  path0  := path2 || path3 || '';'';
  RETURN path0 ;
 END;'
LANGUAGE 'plpgsql';


the result of :

SELECT bdrm_copy('MOHO99', 'test2.txt') AS my_command_string;

is :

               my_command_string
-----------------------------------------------
 COPY ttx_window7 TO '/db/bdrm/out/test2.txt';


Is it possible to execute this line of command? More generally, can one
execute the contents of a variable or a field in postgresql' script?