Several possibilities come to mind:
(1) Check the transmission oil level.  If it's very low, you won't go
anywhere because the torque converter won't have any oil in it to transmit
power.  If the oil is smells burnt and is black, try to change it,
although that's a sign of tranny damage usually.

(2) Is the shift lever moving the shift mechanism on the tranny?  Check it
moving the shifter causes anything to move under the hood - if the engine
was replaced, the tranny probably was pulled and the mech may have
connected something poorly.

(3) Are any warning lights on on the dash?  If there are, pull trouble
codes from the tranny electronics and see what it tells you.

(4) Jack up the front of the car and put it on jackstands.  With the
tranny in neutral, see if turning one front wheel causes the other to turn
in the opposite direction.  If it doesn't, you have stripped cv-joint
splines or worse.

(5) After you fix it, sell the thing and get a 1993-1998 Jetta with a
5-speed and the 2.0L 4-cyl.  Those things are indestructable; the later
ones are weaker, unfortunately, due to excessive complexity.  Either that
or a Volvo 9-series, or Big American RWD Boat (Chevy Caprice, Crown Vic
cop package)...

-Andrew

PS- Why was the engine replaced?  Engines seldom fail in a way that needs
complete replacement, esp in a car of that age.

How many miles on this car?

Has it ever been in an accident/is there rust/is it straight?

What part of the country do you live in?

Ted