All you need is a pattern making router bit that comes with the bearing already attached to the top of it so that when it comes up through the router table the bearing is on the top of the cutter.
Then place your ply on top of your acrylic with two sided tape and route the acrylic while the bearing rides on the plywood's edge.
I bought a small craftsman router table with router included for 89.00 at sears and I have to say it works awesome.
I use Whiteside Downshear Flush Trim #2580 router bits that have a shear angle to the flukes. The cutters are about 2" long with a 1/2" shank for routing 3/4" plywood.
Here is a link: http://www.holbren.com/flush-trim-down-shear/
If you have no experience with the router being attached to the table learn what direction to feed the piece into. My first piece was ripped from the table, hit me in the stomach and flew 25'into the yard. OUCH! Please exercise caution.
Also, there are always several ways to do the same task. This is just my method.
Best of luck,