Move package from one UML system to another?

[Pete]

Hi,

Anyone know how to move a package from 1 UML system to
another?
I am working on a UML file with a few other people. I
made my own copy to work on my package and now want to
move that package back to the UML system from the first
file.
Drag and drop between systems in the tree is not allowed,
there is no copy paste for a package (only duplicate, in
the same UML system).
I am using Visio 2000.

Thanks
Pete