Typically, if the referenced dlls are not in the same directory as the executable, they must be in the GAC. You might be able to use Remoting to get around this.
vb Code:
Imports System.Runtime.Remoting
...
'create object reference to assembly
Dim addOnAssembly As String = "..\My_References\mylib.dll"
If Not IO.File.Exists(addOnAssembly) Then
Throw New System.IO.FileNotFoundException(addOnAssembly & "does not exist.")
End If
Dim handle As ObjectHandle = _
Activator.CreateInstanceFrom(addOnAssembly, "myclassname")
Dim processor As myclassname = DirectCast(handle.Unwrap(), myclassname)
'TODO: use processor methods