You can also download black hairs from the Artbeats site with transparency, or shoot black hairs as Buster suggests.
Try inserting Old Film to an empty Title event and then using Mask Generator to invert it. That might give you what you're after.
Thank you busterkeaton and Spot. Your suggestions worked fine. I think I'm gonna try and find some images of hair to use as Spot suggests. The hair in Film Effect is not very realistic.
I am new to Vegas and videoediting, so I think I have to spend some more time reading the manual and learing how masks etc works. Thanks again.