I will offer what I can, will tell you what can and cannot.
I have made many macros, the biggest one is to handle excels file with 8000~15000 rows and 1000~1500 columns data, what it does is collect them from various locations, do a lot of functions (sorting, comparing, edit, aggregate, ... you guess) then export all into ~1000 new named excel files with desired format within 10~30 minutes running time.