Copy surface between a parts

Hi I have a problem with a comand copy surface   whit Creo 2.

I have  a ASM  with two part, into a second part I have copy all solid surface as reference.

A copy into a ATT20 ... part is make into another ASM and now Is assembly into this ASM

Now I would modify a feature copia1 becouse a part is change.

if I use a second option "REMOVE A EXSTERNAL REFERENCE" there is problem but if I use a first option ....

and copy all solid surface creo give me an error.

Could you help me???

Best regards

Milko