External text with basic html

I am trying to load external .txt files into dynamic text in my flash. I’ve got the text to load in, but I can’t get my dynamic textbox to use html tags.

How do I make the dynamic textbox bold when I put “<b>bold this text</b> and don’t bold this text” in my text file?

also, when I load text from a text file it has to be in a variable like “textbox1=here is all the garbage to go in box1&textbox2=i love super duper textboxes”
I only have one variable per text file, so is there a way to avoid using variables in my textfile? as in can I have a txt file with just text in it (no var names or =) and put that into the desired variable?