Adding References To Script Task

How do you add a reference if the assembly you want to reference does not live in C:WindowsMicrosoft.NETFrameworkv2.0.50727? It doesn't seem to make sense that you cannot access the connections the AquireConnection() method serves since the interfaces are defined in Microsoft.SQLServer.DTSRuntimeWrap.dll (in C:Program FilesMicrosoft SQL Server90SDKAssemblies).

For example the code below works fine, in order to make it work I had to copy DTSRuntimeWrap.dll to v2.0.50727, surely any assembly which is been added to the GAC should be available as a referece?

Public Sub Main()

Dim cmgr As Microsoft.SqlServer.Dts.Runtime.ConnectionManager = Dts.Connections("FTP Connection Manager")

Dim cn As Object = cmgr.AcquireConnection(Nothing)

Dim ftpConnection As IDTSFtpClientConnection90

ftpConnection = TryCast(cn, IDTSFtpClientConnection90)

ftpConnection.Connect()

Dim folders As String()

Dim files As String()

ftpConnection.GetListing(folders, files)

ftpConnection.Close()

Dts.TaskResult = Dts.Results.Success

End Sub