Reading all text files in directory

Question

Hi,
Let's say, i've textfile in D:\files\ as Simple1.txt, Simple2.txt, Simple3.txt. The content of textfile as follow,
Simple1.txt
Next week, i will go to Paris
Simple2.txt
Next month, we play football
Simple3.txt
Hi, my name is Sizuka
How the C# program looks like to read all textfile above and display the content in position 10 to 15 in each file?
Please help