Same video/image on both with a split on the top with a crossfade the length of the change of focus.
On top keyframe a mask around the object you want in focus and blur the bottom track. On the second event on the top track keyframe the other object and do the same. Rinse and repeat as necessary.
Yes... the rack focus in newbluefx is ok.
BUT...the Defocus filter in Vegas (coming from Velvetmatter)
gives absolutely the best depth-of-field emulation there can be,
with many tweaking options. Thats the one to really look at.