Appending text files one to the other

Job ID: 30757216

Budget: $30 – $250 USD

I have two folders, the attached 'largeFolder' consisting of subfolders each containing a number of .txt files, and the forxStocks1day folder, that contains .txt files.
For each of this .txt files there, I want the program to search and find the corresponding file bearing the same name in the 'largeFolder' and append the last n rows of the first .txt file at the bottom of it (I will input the integer n myself each time I run the program, as well as the locations of the two aforementioned folders in my disk). If no .txt file with the same name is found in 'largeFolder', an error message will be recorded in some 'log file' and the program will skip that and continue with the others.
I would like the project to be completed as early as today, since it is a fairly simple task.
Available budget: less than $50, please don't bid for anything beyond that price.