But we had to craft an app to send the order file to the right folder and well, you can get dial up working but I fear you are addressing a portion of the "system."
You've progressed from "log on" to "send in the order." That's quite a leap!
This is like a machine with many moving parts that we get to put together.
Take my advice and have them email it in or place it via your web server. That way any dial up internet will do.
Here's a primer on dial up services on Windows 2008 SERVER -> http://technet.microsoft.com/en-us/library/dd637783%28WS.10%29.aspx