Have a look at WS:Repeat Appointment II for Outlook. This allows you to
build complex appointment repeat patterns as well as adhoc repeat groups
that match no pattern at all.

Features of the WS:RA II add-in:
 a.. Create multiple repeat appointments from the original
 b.. Create Daily, Weekly, Monthly and Yearly patterned Repeat Groups
 c.. On Daily Repeat Groups select what days of the week are to be included
in the pattern (e.g. A part time worker only works Mondays, Tuesdays and
Wednesdays so all other days ignored)
 d.. On Weekly Repeat Groups, selects those days that are to be repeat.
 e.. Once pattern Repeat Groups created, individual dates may be modified.
If for example individual dates conflict with certain events such as public
holidays, these dates can be moved to the following day e.g. Move the Monday
to Tuesday.
 f.. In addition to moving dates it is possible to set different times for
individual appointments.
 g.. Create Repeat Groups that match no pattern using the Repeat Groups
calendar.
 h.. Select an appointment and view the time of that appointment in up to
five configurable time zones before sending invite. Aids the creation of
appointments that span multiple time zones - ideal for international
conference calls.
 i.. Easy to use graphical Calendar interface
 j.. Add additional Repeat Appointments at later stages
 k.. Remove appointment dates from the Repeat Group if they have not
already occurred
 l.. Integrates directly into Outlook and accessed from Appointment Menu,
Toolbar or both
 m.. Available as a FREE 28 day pilot
If you are interested in more details then please go to

   http://www.websetters.co.uk/WSAddIns/Repeat%20Appointment/index.htm

Regards
Graeme