Querying a different sql server from a sandboxed plugin in Dynamics CRM 2011

I am writing a plugin (my first) for CRM2011 which needs to pull some information from a different sql se开发者_如何转开发rver when an account is opened in the CRM. I'd like to run the plugin in the sandbox and am comfortable using ado.net, or linq2sql, or ef. I'm looking for advice on

1. can this be done from the sandbox?

2. which technology should i use so that I don't have to load up a bunch of assemblies that aren't already being used by CRM2011,

3. if I pass a username/password inside the connection string will that work?

Any advice you can offer would be great!

Can't be done from the sandbox. Take it out of the sandbox and the plugin was able to query other sql servers.