Probably it is possible, but on the other hand it may not be possible. Try to check the messages with Spy++ what messages browser is getting when you open the new tab. Off course you need to check this for all major browsers Opera, Safari, Firefox 2,3, IE 5,6,7,8 and Chrome, and make separate functions for all browsers because they are probably not using the same command. Then you need to distinguish which browser(s) is/are installed on the system, check which browser is default, or opened, and then post the message to the opened program.
Again if program is not using any message for opening the tab, then you are stuck.