To Copy:
vim my-file-name
: mouse=a [enter]
Select the text with the mouse while holding the Shift key. This magically copies the selection to the clipboard.
Open Notepad.exe (or whatever) and paste the clipboard data. Remove any tabs as they get all screwed up when pasting into the new vim opened file.
Copy this data with ctrl-c
To Paste:
vim other-file-name
Type i to insert new text.
Scroll to the desired insert position.
Right-click the mouse and the text will paste into the vim instance.