If you have the addresses in Excel, you can do it by a mailmerge with MS Word (at least, I can, so I assume others can do the same). That way, the email goes with the individual email address in the To: field.
Under no circumstances must you put hundreds of email addresses in the cc: field. Some email setups will mean that people have to trawl through pages of addresses before getting to the email. People will complain at you passing their email address on to others without their permission.
Don't do it!
If the other addresses are in an Outlook Address Book, why can't you just send the email directly to that list (but with them in the bcc: field, too?)