Invoke method / Late binding / passing ref variables to a method??

[PJ]

Hello,

I am trying to use late binding to call a COM object.

I am trying to call a 'GetTables' method on the object.
It's essentially a 'MetadataService' which is used to
return the names of tables which are in a specific
database.

the first parameter to GetTables is "in only" (it's a
short - constant which defines types/categories of tables
to look for)

the second parameter is "in/out" (i.e. ref - "array of
objects" used to return the tablenames found for the
specified tables)

What do I need to do in order to invoke this? with two
different types of parameters?

Here's what I have so far...

==== Code begin ====

.... other code here...

try
{
Type metadataservice;
object[] parameter=new object[1];
object MDSvc;
//get a metadataservice object
metadataservice = Type.GetTypeFromProgID
("GMService.MetadataService");

//create an instance of the metadataservice
MDSvc = Activator.CreateInstance(metadataservice);

//Set the parameter I want to set
parameter[0] = objConn;

//Set the Connection Property
metadataservice.InvokeMember("Connection",
BindingFlags.SetProperty, null, MDSvc, parameter);

object[] args = new object[2];
args[0] = MetadataTableConstants.gmmtAnySpatial;

//not sure what to put here (or if this is correct syntax)
args[1] = String.Empty;

//try to invoke the GetTables() method
metadataservice.InvokeMember("GetTables",
BindingFlags.InvokeMethod, null, MDSvc, args);

==== Code end ====