BizTalk 2010: calling a dll from GAC with dependencies

I have to call functions from a custom dll from BizTalk orchestrations (similar to this solution Call a custom .NET component from BizTalk 2006). The dll calls functions of a third party dll, which uses some other third party dlls (we are using to communicate with a legacy system).

The article Global Assemb开发者_如何学运维ly Cache Tool (Gacutil.exe) says that my best bet would be to "include" the referenced dll into the dll I put into the GAC, but I don't know how to do this from Visual Studio (2010).

Any ideas to get this work ?

It looks like putting them into the system PATH solved this problem.