Outlook 2013 search and replace function does not allow for multiple replacements. I searched the internet and someone posted this macro.

Sub ApptFindReplace()
‘ This macro will find/replace specified text in the subject line of all appointments in a specified calendar

Dim olApp As Outlook.Application
Dim CalFolder As Outlook.MAPIFolder
Dim Appt As Outlook.AppointmentItem
Dim OldText As String
Dim NewText As String
Dim CalChangedCount As Integer

‘ Set Outlook as active application
Set olApp = Outlook.Application

‘ Get user inputs for find text, replace text and calendar folder
MsgBox (“This script will perform a find/replace in the subject line of all appointments in a specified calendar.”)
OldText = InputBox(“What is the text string that you would like to replace?”)
NewText = InputBox(“With what would you like to replace it?”)
MsgBox (“In the following dialog box, please select the calendar you would like to use.”)
Set CalFolder = Application.Session.PickFolder
On Error GoTo ErrHandler:

‘ Check to be sure a Calendar folder was selected
Do
If CalFolder.DefaultItemType <> olAppointmentItem Then
MsgBox (“This macro only works on calendar folders. Please select a calendar folder from the following list.”)
Set CalFolder = Application.Session.PickFolder
On Error GoTo ErrHandler:
End If
Loop Until CalFolder.DefaultItemType = olAppointmentItem

‘ Loop through appointments in calendar, change text where necessary, keep count
CalChangedCount = 0
For Each Appt In CalFolder.Items
If InStr(Appt.Subject, OldText) <> 0 Then
Debug.Print “Changed: ” & Appt.Subject & ” – ” & Appt.Start
Appt.Subject = Replace(Appt.Subject, OldText, NewText)
Appt.Save
CalChangedCount = CalChangedCount + 1
End If
Next

‘ Display results and clear table
MsgBox (CalChangedCount & ” appointments had text in their subjects changed from ‘” & OldText & “‘ to ‘” & NewText & “‘.”)
Set Appt = Nothing
Set CalFolder = Nothing
Exit Sub

ErrHandler:
MsgBox (“Macro terminated.”)
Exit Sub

End Sub