As far as I know you don’t need any special port replicator driver. If this port replicator is defined as compatible for your notebook model and you use original Toshiba recovery image it will be recognized automatically and you will be able to use all available ports on this port reflector.
The Toshiba Hi-Speed Port Replicator II is compatible with:
Tecra R700, R940, R950, Portege R830, R930
1. Speeds may vary
2. Ports supported may vary with notebook model; When notebook is connected to port replicator, it is recommended not to use the ports on the notebook
3. Dual VGA and HDMI display capability depends on notebook model
4. Gigabit Ethernet support only if notebook supports it