How to ask a developer about a web based app?

Question: What do I say to a developer to explain that I want someone to rewrite my PC Desktop application code (.Net/C++) into a web-based, platform independent version that won't cost $100K everytime Windows/Word/SQL unleash a new update? Should I ask if he/she can use a particular stack/approach and if so, what is a good main-stream stack/approach that makes sense. Honestly, I don't care what stack/approach, just one that can work, won't get me up a creek without a paddle next year, and one that other developers won't laugh at. Obviously, I'm not a tech founder.