[NTG-context] caption for code listings

hi, I'm currently writing my diploma thesis with context. I already read the wiki and searched the manuals but I didn't find something like a common practice for defining new caption types. My problem: I have a lot of code listings and I want to define a custom caption type (named listing) and aggregate them into a own register. I already set up a new register with \defineregister [listing][Listing] and it is also possible to place listings in this register with \placelisting{ \startJV ... \stopJV } but how can I add a custom caption to this listing? I'm thinking of something like \placefigure. Or perhaps I must just setup placelisting. Any Idea? Thanks in advance! Steffen