Let's make sure we know what you are after - a tag is used in FT to trigger an alarm message. These I have always added and deleted in FT one at a time because generally you don't need too many in order to get a lot of alarm messages. I don't know if there is any way to export them.
An example for a PLC-5 is {::[PLC]B52:300,L64}, this is the only alarm tag in my application.
If you want to export "messages" which may be the case, you can copy / paste them into excel for editing and then copy them back when you are done.
It sounds like you exported the alarm configuration.