Use Ctrl + F to Find (or search) for 199a = The 4th entry under Schedule K-1 Overrides is what I think you are looking for. 

That leads to an entry for Partner 1. You can then use Ctrl + down arrow to get to each of the additional partners. 

Consider what Itonewbie said and possibly reconsider why you might want to (or even need to) use this override. If you have entered all of the depreciable items in Screen 16, with the correct accumulated depreciation and asset acquisition date, Lacerte should do the job for you.