ZIP+4 ZIP codes in Contacts for Samsung Vibrant (Galaxy S)

I have a Samsung Vibrant (Galaxy S) running Android 2.1-update1. I have ZIP Codes for many of my contacts in the ZIP+4 format (e.g. 99999-1234). However, the field for ZIP codes does not allow any character except numbers. Without being able to add a dash it makes it difficult to read (e.g 999991234).

I would have thought that it would auto-format the number they way it does for phone numbers. Is there anyway to have the default Contacts program accept ZIP+4 ZIP code format? Are there any alternative Contacts programs that provide the correct formatting for ZIP+4? Is the Contacts program standard across manufacturers (e.g. part of the OS)?