I have a fixed field length ASCII file that I need to modify specific areas within the file (say line 2 position 4-10, line 3 position 13-19, etc).

I want to have a form that shows the data from the above mentioned lines in their own textbox, then allow the user to change the data in the textbox then save the file.

So, the only thing that would change in the file would be line 2 position 4-10 and line 3 postion 13-19.

What is the best way to do this? Anyone have sample code to get me started?

Thanks.