If you take a look at Sch D, it computes only the 80% limit.  Although some of the numbers are relevant, your input for Sch D doesn't give Lacerte all the info it needs to prepare Sch A and B, which means you will need to populate Sch A and B manually before F.1118 will compute and flow the numbers to F.1120.

You'd think the numbers should flow between F.1118, F.8992, and F.8993 but Lacerte has not been programmed to do that.  That makes it necessary for you to compute some of the numbers offline and plug them in on multiple input screens.

International returns are not exactly Lacerte's forte.  It does a decent job but requires quite a bit manual computation and input.  If you need something more automated, you should look at GoSystem Rs or ProSystem FX.