Apache and LDAP

I’d like to limit access to a web directory to my company.
My company runs Microsoft Active Directory. Can I configure my website to use AD for authentication?
At the very least, I need to know whether DH compiled Apache with mod_auth_ldap.
Then I need some help configuring .htaccess.
I see lots of articles out there that try to explain it, but man are they complicated!!!
Thanks to anyone who can explain it to me … real … slowly … in … short … sentences !!!