set dialerGroup to "OneTel"
set dialerPrefix to "+442070180001pp"
set dialerSufix to "#"
set dialerLabelPrefix to "onetel "
set IDP to "00"
set CC to "44"

to searchReplace(thisText, searchTerm, replacement)
  set AppleScript's text item delimiters to searchTerm
  set thisText to thisText's text items
  set AppleScript's text item delimiters to replacement
  set thisText to "" & thisText
  set AppleScript's text item delimiters to {""}
  return thisText
end searchReplace

tell application "Address Book"
  
  -- Update all the records in the group "OneTel"
  set ThePeople to the people in group "OneTel"
  
  repeat with ThePerson in ThePeople
    
    -- First, we'll clear the old ones
    set PhoneNumbers to the phones of ThePerson
    repeat with ThePhone in PhoneNumbers
      set TheLabel to the label of ThePhone
      if (TheLabel begins with dialerLabelPrefix) then
        -- Effectively delete the old ones
        set the value of ThePhone to ""
      end if
    end repeat
    
    -- OK, make the new ones!
    set PhoneNumbers to the phones of ThePerson
    repeat with ThePhone in PhoneNumbers
      set TheLabel to the label of ThePhone
      if (TheLabel begins with dialerLabelPrefix) then
        -- We can ignore these now...
      else if (TheLabel contains "fax") then
        -- ignore fax numbers
      else
        -- OK, this looks like a good candidate
        set TheNumber to the value of ThePhone as text
        
        if TheNumber begins with (IDP & CC) or TheNumber begins with "+" & CC then
          -- Ignore numbers which are for our local country
        else
          
          if the first character of (TheNumber as text) is "+" then
            set AppleScript's text item delimiters to "+"
            set thisText to TheNumber's text items
            set AppleScript's text item delimiters to IDP
            set TheNumber to "" & thisText
            set AppleScript's text item delimiters to {""}
          end if
          
          set NewNumber to dialerPrefix & TheNumber & dialerSufix
          set NewLabel to dialerLabelPrefix & TheLabel
          
          -- Locate the right phone to update...
          set myPhone to null
          repeat with tmpPhone in PhoneNumbers
            if the label of tmpPhone is NewLabel then
              set myPhone to tmpPhone
            end if
          end repeat
          
          if myPhone is not null then
            set the value of myPhone to NewNumber
          else
            make new phone at the end of phones of ThePerson with properties {label:NewLabel, value:NewNumber}
          end if
        end if
      end if
    end repeat
  end repeat
  
end tell