When MSDE is installed, a port is randomly selected. If you do not specify the correct port, you will not be able to successfully connect to the MSDE Timeless database.
First, determine the port MSDE is using. Then, during the Timeless Time & Expense Multi-user specify the server as the IP address of the server, server port. Ex 111.111.111.111,1234 where 1234 is the default port from the previous step.
You will also have to configure your firewall to forward all traffic on the specified port to the server TimelessMSDE was installed on.