Generating # of letters and making them "_"

I am trying to create a hangman program. So far I am trying to generate the number of underscores per word.

EX:

Cat

_ _ _

We have a variable that stores the number of letters in the word and I am trying to generate X amount of _ for each letter in the word.

What would I go about doing that with?

I tried a for loop but that wasn't what I wanted

I have

$lettercount which equals to the number of letters in a word (int)

Just stuck on how I am to make that number of letters in to _

Any suggestions?

Thanks,

Ryan