MSSQL 7.0 replication through internet

SQL Server replication requires that both servers be on trusted domains with each other (i.e. a two-way trust).

This cannot be done with an Internet connected SQL Server.

The only alternative ( that may, or may not, be an alternative) is to make the connection via a VPN.

You can set this up across the internet using one of the wizards. I'd recommend "snapshot replication". Normally, LAN replication is set up using UNC and across internet you need to use ftp connections. The best place to begin is Microsoft's Technet site for SQL.
http://www.microsoft.com/technet/sql/replica.asp

"Configuring Replications for the Internet
Making a snapshot, transaction, or merge publication available to subscribers connecting over the Internet or a corporate intranet is as simple as marking a check box in a publication's Properties dialog box when you're creating the publication. Both push and pull subscriptions can be enabled to use the Internet in this way.

For a snapshot publication, the subscriber connects to an FTP server at the publisher to retrieve the synchronization sets that initialize the publication. After that, the Merge Agent or Distribution Agent connects over the Internet to deliver updates at replication time."

If you can Ping the sever in question, then NT 4.0 should need no further configuration for replication (other than normal admin duties of course).

Launch the MS SQL 7.0 Client Network Utility, and register the remote server here first. Just usethe TCP/IP network library for less hassles (unless you are using NT Autointoxication in which case stick to Named Pipes) supply the IP address, and Bob's your uncle.

Now within Enterprise Manager you can add this Registered server to your servergroup list, and It should just be a matter of course setting up replication between the two from this point on.