>>

>>[DllImport("ww_local.dll")]
>>static extern string Invoke1(string cInvokeString);
>>

>
>Should this dll still be in the References of the project?
>
>Also, once declared this way, how should I call it?

No, it doesn't need to be in References.

Once it's declared it's basically just a static method call.

string result = Invoke1("StringHere");