php and custom plugins

i want to know how i can open a specific form rather than the standard form iam using buddypress plugin and buddy press simple front end.

i have followed the directions here but have trouble knowing how to call the correct form so far its calling the standard form i would like to show a custom form.
i was able to use code below to show a form on the messages tab of my site but thats all i can manage.

//now let us find the form and render it

$form = bp_get_simple_blog_post_form( 'my form' );
if ( $form ) {//if this is a valid form
$form->show();//it will show the form