SQL> create function param_passing_demo ()
{
  declare stat, msg varchar;
  declare mdata, rset any;
  exec ('SPARQL SELECT ?s WHERE { graph ?g { ?s ?? ?? }}',
    stat, msg,
    vector ( /* Vector of two parameters */
      'http://www.w3.org/2001/sw/DataAccess/tests/data/Sorting/sort-0#int1',
      4 ),
    10, /* Max no of rows */
    mdata, /* Variable to get metadata */
    rset ); /* Variable to get result-set */
  if (length (rset) = 0)
    signal ('23000',
      'No data found, try demo database with installed Virtuoso tutorials');
  return rset[0][0];
}

SQL> SELECT param_passing_demo ();
callret
VARCHAR
_______________________________________________________________________________

http://www.w3.org/2001/sw/DataAccess/tests/data/Sorting/sort-0#four

1 Rows. -- 00000 msec.