Tip: Be more clear in your questions. Also, its a good practice to place your question in the post you make even if you do it in the subject of your post.
I'm not exactly sure what the question is reffering to, but from what I can understand your trying to increase the font-size of text inside a file. I'm also assuming you retrieve the file somehow to work on your ASP page.
Text in files isn't stored formatted unless the file type allows it. So text inside .txt files is only text, formatting has to be done to the text after it is been retrieved.
If you can clarify, I can help more.