I don't think this is possible but maybe one of you javascript gurus will prove me wrong

I've got a input box form field value called "Name" that I want a user to be able to click a "copy" button which would automatically copy the value to another form field in a separate window (in a different application)

I've got full control over both applications so I can amend any window, form, field names etc.

Basically I want to negate the need for the user to have to manually copy and paste the data from one field in one application to the same field in another application.

Anyone ever done anything like this?