Can I convert elemental nitrogen to nitrous oxide?
There are several ways to fairly safely make $\ce{N2O}$ in the laboratory that don't involve the difficulties associated with trying to react molecular nitrogen.  The following reactions all are mentioned in this Wikipedia article which I suggest reading, along with the references.  Depending on the quantity you are making, I'd be very cautious about using the thermal decomposition of ammonium nitrate as this can kind of blow up on you (literally). Of course every reaction has it's own risks and it's up to you to decide what you are most comfortable with. 

I think the direct oxidation of ammonia over a manganese dioxide-bismuth oxide catalystis an intriguing method$\mathrm{^{(1)}}$   

$$\ce{2 NH3 + 2O2 -&gt; N2O + 3 H2O}$$

This also seems like a fairly straight-forward route:  

$$\ce{2 HNO3 + 8 HCl + 4 SnCl2 → 5 H2O + 4 SnCl4 + N2O}$$  

And this seems to me a bit of a more complex synthyses:  

$$\ce{2 (NH2)2CO + 2 HNO3 + H2SO4 → 2 N2O + 2 CO2 + (NH4)2SO4 + 2H2O}$$

Again, I'll say molecular nitrogen makes a lousy starting material for most syntheses, including $\ce{N2O}$.

1) Suwa T, Matsushima A, Suziki Y, Namina Y (1961). "Synthesis of Nitrous Oxide by Oxidation of Ammonia". Kohyo Kagaku Zasshi, Showa Denka Ltd. 64: 1879–1888.