Not sure it will work in 10.0.1, never used that version, however. If you have a "Network" Pref panel, use it and make sure the internal modem option is enabled in the list of "Network Port Configurations" ( we're not actually going to use that, we just need to be able to access it's screen ). Now the Modem should appear in the "Show: ...Configurations", Select it, click the "Modem" tab and deselect "Show modem status in the menu bar".
If you cannot access "Internal Modem", try creating a "New Location" and see if it appears in any list. If so, then use the above steps.
As long as you don't click the "Apply Now" or "Assist Me" buttons, you will never actually create a new location but you can access all the 'stuff' you want. And you may also get a dialog asking if you want to apply the changes you made, just click "No" and you'll be fine. Even if you accidentally apply any changes, you can always go back to the "Location" you already had set up for the DSL and re-apply it.
Hope this is close to what you have in 10.1.