How to loop over files in directory and change path and add suffix to filename

I need to write a script that starts my program with different arguments, but I’m new to Bash. I start my program with:

./MyProgram.exe Data/data1.txt [Logs/data1_Log.txt].

Here is the pseudocode for what I want to do:

for each filename in /Data do
  for int i = 0, i = 3, i++
    ./MyProgram.exe Data/filename.txt Logs/filename_Log{i}.txt
  end for
end for

So I’m really puzzled how to create second argument from the first one, so it looks like dataABCD_Log1.txt and start my program.