howto allow users to edit own threads in moderation queue?

[j0rd]

Here's the deal. I've created a perl cgi where users can buy VBulletin threads for events. The users enter in some initial data for their thread and associate an image with it...I create the thread and want to hide it from everyone, until the paypal transaction is completed. Once the user is done with paypal, i direct them to edit the body of their thread (this is the first they are able to do so, the other data they entered before i use to create the title for the thread and figure out how much to charge them for the thread). I send them to:

/vbul/editpost.php?do=editpost&p=110 (where 110 is the postid)

Now the issue is, if i want to hide the thread from the users, i can set the thread to visible=0, but then they're not able to edit the post. What's the work around for this?

If you've used paypal before, you know that the transaction takes a couple seconds to complete before the POSTBACK is sent to your postback script (ipn), so i fall into this state where i want the user to edit the body of their thread, but i can't display the thread to all the users until i get the postback from Paypal.

Any help would be appreciated. Essentially what i need is "Users able to edit own threads in moderation queue".

Has this been done before? ANd if so where? I couldn't find anything about it by searching the forums here. I did find this on vbul.com though:
http://www.vbulletin.com/forum/showthread.php?t=184468