You can connect to your access database by using a standard Access Connection String.
"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Inetpub\wwwroot\domain.com\db\mydb.mdb;User Id=admin;Password=;"
If you created the database through the HELM Control Panel your database is located at C:\Inetpub\wwwroot\domain.com\db\mydb.mdb
Be sure to replace mydb with your actual database name and domain.com with your actual domain name.
You can verify the path to your db folder by viewing the Web Site Settings panel.