I didn't understand what you suggested.
Let me elaborate the requirement further:
I am viewing the UCM iFrame in Siebel and it shows the various attachments to a Siebel entity. A checkbox needs to be added to select multiple attachments at a time. Requirement is to copy the selected attachments to another Siebel Entity on click of a button(custom).
The functionality that exists by default allows you to update each attachment manually, but i need to do it for multiple attachments at a time.