Here is the way to use odbc_columns() with "Attunity Connect", an ODBC connector to VMS :
$db = "my_database";
$table = "my_table";
$con = odbc_connect($db, "user", "password");
$result = odbc_columns($con, $db, "", $table, "%");
while (odbc_fetch_row($resu)) {
echo odbc_result_all($resu);
}