Any decent hardware store should be able to provide you with something (take a photo from the Net with you).
BUT
You can get a dedicated machine with water cooling and a guide fence for a grand or so on Lazada.
Is it worth messing about with a less than ideal solution??
EDIT We have a little Ryobi which cuts tiles, concrete slabs, concrete (for chasing out pipes) or Shera board, and it came with a small circular saw blade which I've never used (we have a "proper" circular saw).
If you want to cut curves a small angle-grinder with a diamond disc is your friend, it can also cut or grind steel (use it to sharpen the mower) and sand wood (a bit vicious in my hands to be honest) with the relevant disc installed.
ALWAYS wear eye protection!!!