When Six mentioned Ctrl-J, he spoke of the CLUA console. It's easier to manipulate than Shadowkeeper (a "trainer" program that allows you to cheat and/or fix mistakes), plus you don't have to quit your game to use it.
How to activate the CLUA console:
- Open the baldur.ini file in your BG2 directory. It should open in Notepad or Wordpad.
- Find the section named "Program Options"
- Add the following code exactly as it is written here to the bottom of the Program Options list: Debug Mode=1
- Save the file and close.
- Start up BG2.
- To activate the console, on the main screen, press and hold Ctrl then press Spacebar. If you've done everything right, a new text box should appear at the bottom of your screen.
- Simply press Ctrl + Spacebar again or switch to another view (inventory, spells, etc.) to close the CLUA console.
The Ctrl-J trick can be used without opening the console text box. Just select your entire party, move your cursor where you want your party to go, and press Ctrl-J. You might have to do this one at a time with each party member, or you might be able to move them all.
And a final hint, don't transport them TOO far past the bridge.