I need a programmer to change an txt file

I neen a program that automatically changes some values of a txt file and saves it.

The program should change a numerical value in a desired percentage. For example, if the value is 100 and the desired percentage is 80% the final value should be 80.

It would be interesting that the changing percentage could be an aleatory number based on desired number plus/minus a tolerance factor. For example, if I choose 20% and tolerance is 20% the value could be changed in any number between 16% - 24% always positive whole numbers.

There are two types of files:

FILE 00- Data is separated by semicolon (attached as FILE 1) - The number to be changed is in position 9
FILE 16 - Data is separated by fixed lentgh (attached as FILE 2) - The number to be changed is in position 426 and 432.

The process should be:


1. Ask which filed needs to be changed
2. Ask type of file (00 or 16) / destination folder/ percentual change/ tolerance
3. Launch process

Percentual change an tolerance should be 20% an 15% as default.

File name as default should be type of file_date_hour f.e 16_23032018_1758