I have never done a partnership return with 16c foreign gross income.  

My understanding/observation has been that 16b is the sum of 16c thru h.    All K-1's i've handled have been this way.

Therefore in Lacerte personal entry screen 20, the Gross income CDEFGH is basically 16B.  The info there would flow to  form 1116 Line 3d for that particular foreign country.  (You first set up the country in Screen 35 and cross reference to the country in Screen 20.)  This way, you handle the FGI in Screen 20 without having to do a separate workpaper for Screen 35. If you have a workpaper, it would be more like a control worksheet and you would have to check the numbers if the total is off from Lacerte 1116. 

My guess for Line 16b, as itemized by 16 c e  and h has to do with the allocation to the partners.  16 c has to be allocated to the particular partner because the FGI was generated at the partner's level.  16e and h would be allocated based on the partnership percentages, but would be just an educated guess without further research.  As i said i haven't dealt with a 1065 that has 16c gross income.