Why in the world would you want to use NumLock?
If what you want is just 1 special character like a ♥,
then go into Microsoft Word and do "Alt I S" (which
is the "Alt" key, followed by letter "i" and "s"). After
that, scroll down until you see the symbol you want
and then click on "insert".
The name of the font within the grey box should be
"(normal text)" within brackets. If it isn't, then click
on the ▼, scroll to the top, and click "(normal text)".
You should be aware, however, that YouTube does
not allow any characters such as these to be used
in either usernames or comments.
If you are keen on what lots of teenagers are doing
with their profile boxes within their channels, most
of designs that you see are actually "cut-&-pasted"
from various websites.
This fad now goes by the name of "ASCII art". Just
for you, I've included here 3 very popular websites:
www . geocities . com / SoHo / 7373 / how to . htm
http://www.geocities.com/SoHo/7373/howto.htm
www . ascii world . com
http://www.asciiworld.com/
www . chris . com / ascii
http://www.chris.com/ascii/