missing Microsoft.SqlServer.ManagedDTS

Hi

I am trying to run a SSIS package first time through vb.net console application. As the first step, i was trying to add the reference for Microsoft.SqlServer.ManagedDTS assembly but it was not in the available assemblies list box in visual studio 2003!

Please guide what i am supposed to do to get it, or if there any other alternative.

Thanks in advance

Utsav