[exim] Exim & Dovecot - one authentification file

Hi! It's my first post here (frankly i'm new to the whole idea of mailing
lists, never used them before), but i hope i wont mess up anything.

I'm installing a fresh e-mail server for our company. Decided to use
exim+dovecot. First i installed exim, tested it. Everything went ok. I
wanted to reject all mail to the recipients that do not exit on my domain,
so i created a file /home/mail/users with local parts of address. Each line
is a local part. Edited exim.conf : "acl_check_rcpt: accept local_parts =
lsearch:/home/mail/users" so i accept only mail for existing users. Then i
installed dovecot. We do not have many users, so i want to store userinfo
in a file not db. Logically i though i could just add :{MD5}password to each
line in the users file to use it both for rejecting mail and authenticating
dovecot users. After i did add passwords dovecot worked perfectly but iexim
reject all mail. I understand that lsearch does not do what i want. So i
tried to find some info in spec.txt and have found wildsearch function. The
problem is that i cant figure out how to compose expression that will check
local parts denying the end of the line with password. I cant even find an
example of wildsearch usage. Really want to make it work.

Thank you.