Default Vim - no esc key?

Hi, I'm using Nexus 7 with stock JB system, with a usb keyboard, and when I use Vim both esc key and ctrl produce a ^@ character. I wasn't able to use mappings with ^@ char to get anything working (most importantly ctrl-[ for escape).

At the very basic level, I'd like to get Esc working, but ctrl would be really great, too.

I can see that android itself does understand ctrl key as a modifier, for example to jump over words in any editor by using ctrl+left/right.

How can I get this to work? It seems like such a tiny thing but it keeps me from being able to write code on N7, write and edit longer text documents.

Any help / hints appreciated!