Visual Basic Client communication to 4GL server process

Hello, what methods should i use to establish communication between VB Clients and and server process written in 4GL running on our SNI RM servers? The task of the 4GL program is to make complex calculations using lot of data from the database and the VB Client should only provide the GUI (taking initial start data, presenting results, informing user about errors,etc). Is DCOM from Microsoft a method which could be used here? I think DCOM implementations are also available for Unix, am i right? Will this work together with 4GL? Is CORBA what i should look for. Just give me a hint where to search for detailed information. Greetingsm Joerg