You've already figured the answer out yourself: You'll need two appointments.

Signature
Sue Mosher, Outlook MVP
Author of Configuring Microsoft Outlook 2003
http://www.turtleflock.com/olconfig/index.htm
and Microsoft Outlook Programming - Jumpstart for
Administrators, Power Users, and Developers
http://www.outlookcode.com/jumpstart.aspx
>I can't seem to find where to set the frequency of an appointment to be
> bimonthly (i.e. 1st and 16th of each month) withou having seperate monthly
> appointments. Can someone please point out my blindness?
>
> Thanks,