That would be me, then!
As far as restrictions go, as long as you are granted a Tourist Licence (Licencia de Viviendas con Fines Turisticas you can let out 2 separate properties (what we'd call an "entire apartment" here on Airbnb) or up to 5 rooms (but if you do this you must live on the premises yourself) in one property. Any more than this and you come under a different and more stringent regime.
Applying for the licence is bureaucratic, but reasonably straightforward if you speak Spanish. If you don't, I advise getting a lawyer or gestor to help you. In fact the best thing I can do for you is suggest you read this site which will give you the basics.
If you have more specific questions (I'm not sure what you mean by the Host Management system) perhaps it might be best to pm me, as this may be a topic of minority interest.