"Splitting" a com is not as easy as it might seem. In general serial ports are intended for direct communication between two devices and there is rarely provision for a third device to be involved. In some cases you may get away with it, if the third device (or software) only listens to the serial data stream. VirtualVP gets around this by acting as a buffer, VirtualVP is the only software in such a setup that actually communicates with the Davis weather station, and then it uses virtual serial ports to send data to other programs. It will not work with an OS station though, as it has no knowledge of the OS serial protocol.
Some weather software programs have a "listen only" option, if one of the programs you are using has such an option, it may be possible to make it work.
As it was brought up, the Vue uses the same protocol as a VP/2, so VirtualVP will work with any of them. The only thing I'm not certain about is whether Steve has added support for "LOOP2" yet.