changing id of the existing object

hello experts

please help me to solve this problem.we created an object in the A system and at the time of changing the version we copied it to some other intermediate system.when we want to copy the system into B from where we can send it to A we are not able to create the transport because the id of the object is 'b' becuase it is created in B system.We therefore cannot create a transport for the object but a only "repair".pls tell me where i have to do this repair and explain me indetail the efects of this repair on the other systems.

thanx in advance.

giri.