Underlining wrong word in text file

[XerXes786]

Hello Everyone,

So I'm supposed to create a spellcheck program which reads the input file from a user and compares it to the dictionary to find the misspelled words and gives a list of suggested words. So far, I've programmed it perfectly however I'm stuck at the last part where I have to copy the input file to a new Text File and underline the misspelled words. I have no clue how to do underline (----) the misspelled words right below the word. So the idea is that it goes to a new line below the word and inserts "----" as an underline.

So can anyone please provide me with some hints or codes? I need help as soon as possible

Thanks!