Can a Custom Object on an Oppty be Moved to Another Oppty?

[thusker]

We use a custom object on Opportunities for non-standard discount requests.  From time to time, a rep creates the custom object on the wrong opportunity and does not want to redo their work.  As far as I can tell, there is not a way to change the "association" to a different Opportunity and move the custom object to the right record.  Is that correct?  Is there a way to move a custom object from one opportunity to another?

I was hoping that it would work like the association from an Opportunity to an Account . . . where you can just look up or enter a different Account name and move to record if it's in the wrong spot.  But I think I am out of luck.

[Harry James]

Maybe I don't understand.  If the custom object has a relationship to the Opportunity object, isn't there a relationship field on the custom object?  Might that relationship field not be on the custom object page layout?