even if you where to by pass the lightning bolt for the trigger, you will still need it to set the value.
if you don't want to set up a local testing server, you can set up DW to connect to the remote server in the testing server settings using FTP.
the long and short fit is that in your Site Definition, you need to set up a server that DW will connect to for testing. this can be a local server, or the remote server. but it is needed for dynamic development.