Mainframe, MVS and zOS Discussion

I am working in a new mainframe project. And here, I see applications that are written in Java but interface with CICS regions. How do they do it? For instance, if I want to connect to mainframes using VB, what can I use to connect to a z/OS Mainframe?

Any documentation or sample code in this direction would be much appreciated.

Did you not get anything when googling, or asking your colleagues or your networking guys?

I aksed to the colleagues but they are from mainframe side and don't know much about it. There are stored procedures written to send the data to front end java screens but I'm asking about the set up at system level.

As an application programmer, there is little you can do except talk to your site support group.  CICS, for example, has a Web Interface component that listens on a particular TCP/IP port (and this port MUST be uniquely assigned to the CICS region for the entire LPAR) and responds to requests on that port.  There is software that can be installed on a mainframe to listen for requests on a port and respond to them, but such software needs to be installed and customized by your site support group since it is vitally important that none of them use the same TCP/IP port.  It is possible that your site already has software it is using, and it is also possible that such software would have to be purchased and installed.  Without such software, you can send requests to the mainframe all day long but you'll get nothing back since the mainframe won't know you're attempting to talk to it.