[exim] Resend email

Hi

I have a mail (which I got through pipe transport), thus it is one file with
all headers and content.
Now I want to resend that mail through exim to another address.
Perferably I would like to call something such as:

exim4 (someoption) message.eml fromuser@??? touser@???

Is there a way to do this?
I must admit that I do not fully understand exims parameters so far.

If it cannot be done with exim directly, is there another way?

Regards,
Steffen