Here is a script for configuring WSS 3.0 installation without Active Directory, where SQL Server resides on a separate box:

psconfig -cmd -configdb -create -server DBSERVERNAME -database wss_admin_config -user WSSSERVERAppPoolAccountName -password p@ssword -dbuser SQLDBUSERNAME -dbpassword p@ssword -admincontentdatabase wss_admin_content

Based on the post here:
http://blogs.msdn.com/fooshen/archive/2007/02/01/installing-moss-without-ad.aspx