How can I insert new fields within an existing admin form via plugin/hooks?

[SToP_GAP]

Hi, I hope someone can help...

I'm trying to extend the forum.php admin form by adding a few custom fields in there. I won't get into what those will be and explaining all that... basically if someone could show me how to add a direct copy of the "Title" field directly after that in the forum this would be most helpful.

Line 140 of forum.php is:

PHP Code:

print_input_row($vbphrase['title'], 'forum[title]', $forum['title']); 


I have a product & plugin defined and using the "forumadmin_edit_form" hook I can execute code just fine. What I can't work out is how to "inject" at a certain point in the output.

Essentially if I were hard editing the forum.php file, then I would copy line 140 and paste it again as line 141. How do I achieve the same from a plugin?

Many thanks