Reference of a Web Service from another Web Service

Hi! I don't know if what I'm asking is a basic asp.net question or if I'm asking the wrong question but I need help.

I have a main Web Service with different methods, and another 3 or 4 web services that use different dlls. I have a database with a table that stores and relates each method with the Web Service it should use. What I need to do is:

1. Select the web service's url/name from the database and make the method reference it and use it, being able to use it's methods. This, being done from the main Web Service and not the Web Page.

2. Being able to change from the UI the reference of a method in case I want it to use another Web Service instead. I believe this would only be an update to the database from the Web Page right? The thing is, I'm not sure how to connect to a database from a html page.

Thanks in advance for your help, sorry if the problem is not clear enough, ask if I left an explanation out or if something isn't really explained