How do I configure ELMAH programmatically?

I'm interested in using ELMAH but need to configure it programmatically. We have existing infrastructure for determining connection strings and the like, and can't code them into Web.Config.

How do I go about using ELMAH in this case?

From stackoverflow

• This should get you setup:

  http://www.codeproject.com/Articles/66610/Dynamically-setting-the-Elmah-connection-string-at.aspx