Control the climate control on smartphone?

yes indeed there is a way however you would probably need an internet connection in your car for it to piggy back on. if your car has an auto start you could probably jury rig something together. it will depend on what car you are modifying.

I'm actually modifying my dashboard and i want to get rid of the climate control or hide it somewhere because there's no space to fit it in, so basically i just dont want the actual climate control to be seen, but want to control it on my phone instead

If you are an electronic wiz it could be done but the fact that you are asking here indicates that you don't have the skills to do such a job.

You would need to build a device that can "talk" to the climate control system and your phone and then write the software to create an interface and menu (app) that you could control with your phone. I am guessing that a few million in development costs might do the trick but then you could market the system and make billions and billions ;)

One last thought. This is really a project that could only be done successfully by a car manufacturer but they would never do such a thing as using your phone to control your car systems while driving is dangerous.