Ask those who created the premapper.

who are those and where can i find them?

No idea, read the docs that accompany the build or check where you downloaded it.

I read the docs and it didn't say anything about the F-Keys. I downloaded the dosbox for here.
I can see that the normal keys get their ascii value (in hex), but i don't know why 275 is, for example, chosen to be the right key.

Then check the link that was posted in the same thread.

what link?

That link that was posted there.

premapper is of the s60dosbox.sf.net
port

I've read the whole 10 pages twice and i haven't seen any link that can explain how to map the F keys. If you know how or have that link please tell me.

there is NO premapper in dosbox.
It is part of the s60dosbox port. Ask there. I posted the link above

Closed, and next time don't post in the dev forum for stuff like that.