Theoretically, and with a lot of work, yes, it can be done. How? It's not worth my time explaining it when you could look up much easier syntheses yourself. Were you to mix it with NO3 gas, you'd have a lot of problems. No, it would not have the same effect as potassium nitrate, because one is a mixture of an unstable reactive gas and a free alkali metal, and the other is a salt.