I bought Cortex command about 2 years ago. Since then the desktop i was using has broken down. I've saved up, sold most of my valuable things, and been helped out by family to buy this laptop, but I no longer have the money or income to spend on new games (especialy ones I've already purchased). Is there any way that I can get another key code?

You're going to want to contact this guy and see what you can do about getting your key code back, then you can get the latest version of Cortex via licensing.datarealms.com using your email as the username and the code as your password.
As an added bonus, any version you get through that link does not require the code for any registration process as before, it will work as a full version no matter what computer you put it on.