Yes, you're right about that. She is valued by some, but I'm highly valued and I am in a stable position. I have gathered I quite unique expertise in my company that can't be missed or replaced in a acceptable amount of time.
I know I just can set off an 'eleminationproces' by bringing this incident casually up while talking to some keyfigures
That is what you should do. She's already proven herself capable of deceitful behavior. Confronting her could very well just provoke her to take prophylactic action against anything you might do, such as taking steps to denigrate your credibility among the senior management, even going so far as to completely fabricate things. You have to retaliate where it hurts - through her credibility.
After all you don't want to have misunderstandings and bad emotions mixed in the workplace, you need to have all the facts before you act. But then, if she was a bitch to you just go ahead and screw her... Because you can.
I love all of your ideas (great creativity, wonderful hatred ).
Now, I'm gonna play old, boring 'J' who's been there. (I worked in HR actually for quite some time). What I'd do is this:
Come up to her, told her that you know (it doesn't matter that she knows, that you know - by telling this you make things clear) and say something like:
- OK, you owe me. What can I expect from you in return for this?
I think it's the best way to go and you'll be 'double-winning' since some executives know that it was your idea. You'll get the credit (believe me, it will spread that it was your idea) and she'll owe you. Not to mention that she'll know that you can stand for yourself and it probably won't ever happen again. You'll have your revenge too, since she probably thought she totally got away with it already.
That's all. Peace out. Extraverted Feeling in action.
"Act as though it was impossible to fail."