How about this? It's in SQL. I don't know how to do it in Oracle...

Code:
Dim cmd As New SqlCommand
If <admin> Then
cmd.Connection = New SqlConnection(ConfigurationManager.ConnectionStrings("AdminConnectionString").ConnectionString)
Else
cmd.Connection = New SqlConnection(ConfigurationManager.ConnectionStrings("UserConnectionString").ConnectionString)
End If
Code:
<add name="AdminConnectionString" connectionString="Data Source=ora_admin;Persist Security Info=True;User ID=SA;Password=PASS;Unicode=True"
<add name="UserConnectionString" connectionString="Data Source=ora_user;Persist Security Info=True;User ID=SA;Password=PASS;Unicode=True"