Automating CSV file merging and cleaning preferably by using Batch or Powershell : I'm not a code guy and have spent whole day trying to get this done without success, hoping I can get some help from the experts. 

I have a folder called Vehicles, within which are two sub-folders - Automobiles and Trucks. Each of sub-folders contain two CSV files which have identical (to that sub-folder) headers/structure.
What I'm trying to accomplish:

1. Take the two CSV files in Automobiles folder merge them without duplicating headers and name the merged file as Automobiles.csv
2. Delete all rows in Automobiles.csv where 6th column (header is Fuel_Type) is "Diesel" (without the quotes) then move the file from sub-folder to main Vehicles folder.
3. Take the two CSV files in Trucks folder merge them without duplicating headers and name merge file as Trucks.csv
3. For merged file in trucks folder remove all rows where 6th column (header is "Fuel_Type") is "Diesel" (without the quotes) then move the file from sub-folder to main Vehicles folder.
Obviously if someone can help with 1 and 2 I can manipulate it for 3 and 4.
5. BONUS POINTS :) take the Automobiles.csv and Trucks.csv files and create Vehicles.xls file with Automobiles and Trucks tabs.

Few details - files are pretty large, each CSV can up to 350 thousand rows x 150 columns and be 200 MB in size each. All the Batch scripts that I tried to put together removing headers seemed to freeze with larger files.

Due to user permissions  on work computers would strongly prefer to use something that is native to Windows7/8 and doesn't require additional software, but would consider other options if nothing native is available.

Thanks in advance!

