InfoPath Dev

Im kinda stuck on this issue and im hoping someone here has some advice to help me out. 

I have a IP form that allows users to submit new cost savings project ideas and submitting the form kicks off a kinda complex approval workflow up to 4 approvers depending on the department, etc. Everything works great up until it is rejected. Once the project is rejected, the submitting user gets an email to make whatever updates and then will resubmit, continuing at the approval step that the project was rejected at in the workflow. My issue is that when they resubmit the project, it creates a whole second form in the form library and the form that was rejected just sits there, practically a duplicate other than whatever change the user made.

 My question is.. Is there a way to update the form and submit without adding a whole new copy of it to the form library? 

Also, custom coding is not an option. every bit of logic has to be done in IP and Workflows

 Any advice is greatly appreciated.

Thanks

Hey there -- the form submits to the library, right? Does the "copy" have a different name than the "original"? You can set your submit up to overwrite, but have to make sure your fields used for name won't change on subsequent submits....

 Well, this is where i have some decisions to make. Previously when i handled the form submit (at the time of my initial post here), i appended the date and time just after the project title so it would be something unique like "My Cost Savings Project - 12162010094423" -- However,  doing this would create a separate form each time which is not what i wanted. My other option was to do something like append the username after the project title like "My Cost Savings Project - MattV" which would allow me to update that form and not create a new one, but the problem with this is that there is a potential that the user could use the same project name for multiple projects. So if they created a new project with the same name as another, it would overwrite that other project without ever telling the user that it did. 

 I was thinking about creating a web service to check if the file name was already taken and if it is, tell the user to use another name, but i want to avoid this unless i need to. Trying to be as flexible to the user as possible without losing integrity.