Changing Password via CMD (looking to create PW with spaces)

[kapura.ftw]

I found the syntax to change a user password through command prompt. I am using:
net user username password

I have sucessfully changed the password to a regular password. I can not figure out how to change it to a pass-sentence. How would I write the syntax for a password with spaces in it? 
For instance, please explain how I would write "My new password." in cmd...because this doesnt work:
net user testuser2 My new password.                                   

I am sure that it is case sensative, no? If its case sensative for the password, why wont it recognise the sapces as part of the password? 

Thank you for your time.

[kapura.ftw]

wow, sorry thats so messy. still trying to understand all the errors i get when i try to post!!!

[CimmerianX]

Have you tried
net user <user> "this is the password"

I don't know if that will work but worth a shot. ALthough you may end up with a password being "this

[kapura.ftw]

thats perfect. im still so new at this, using quotations would have never crossed my mind. thanks!