I've got an application and I share it with some companies however this application is not free nor for sale. It's just some private project which I don't want to share with world but only some companies that I'm working for.
But simply I don't want them to:
my application or any part of it.
What kind of a license I need? Can I just knock up some lines sort it out?
I was hoping to find something similar to Creative Commons
You should really, really ask a lawyer about this. It's highly unlikely that a layperson is able to come up with a reasonably flaw-free, working, and actually enforceable license agreement, just as it's not likely for someone with no programming experience whatsoever to write useful software. In case you're considering it. you also shouldn't copy license agreements verbatim from somewhere else without further research since the text of those license agreements may not be legal to copy.
In short, if you need a license agreement, you stand to potentially lose something, and in that case you should ask for advice from someone who knows what to do.
(edit as response to OP edit) The CC licenses were devised by lawyers, i.e. by people who have studied and are qualified to write legal code. They did the (very hard) work of providing easy tools on how to apply that code to your work. That's why it looks easy. If you start from scratch, it's definitely not easy. Of course, you could whip up a few lines. but you should do that only if you don't plan on having to enforce that license in court.
These sort of situations are (legally) complicated, and to echo the other answer - get a lawyer. If you don't stand to cover the costs of that then don't share the code with those companies (unless you want to apply a pre-made CC or Open Source licence).
I think in theory you are protected by copyright law, but it might depend on where in the world you are. Things like copy and share are forbidden in copyright law so it doesn't require a special license. Make sure to claim the copyright somewhere in the application (like splashscreen or about box).
It looks to me that you sort of trust your users, so maybe the simplest thing to do it to not provide a license at all. In the splashscreen add something like "Can not be used without a valid license from...". That makes ot illegal for them to use the application, but I guess you won't bring them to court.