I found this web page that talks about converting from Wingdings to Unicode.
Based on this, I found that
produces the character you are looking for. You don’t need to choose the Wingdings font, this will work with the regular system font. So your formula will look like this:
You could use ¶ instead of cr() if you like. Also, you could simply use something like this:
Just replace 3 with the actual number of boxes you need, or use a variable. The text funnel on the end strips off the last carriage return, you may or may not need to do that. You could also use the strip() function to do that.
Using this same technique you could also use a Font Awesome character, though you would have to make sure to choose the Font Awesome font.