What my program did was monitor the savegame folder on your friend's computer, and whenever a new turn file appears, it brings up a message box offering to start SE4.
It was only for sequential play, and there was a bug in SE4, such that loading from the command line caused all your ships to have 0 movement. You had to reload the savegame, and then everything worked.
In any case, the result was that my program only told you when the other player is done, and loaded SE4 (not the savegame).
Someone else went ahead with a simultaneous game helper, and I left it at that.
AUB's LAN Helper
EDIT: Fixing URL
[ 25 December 2001: Message edited by: suicide_junkie ]