The prefix "punct-" usually relates to piercing or pricking rather than "point" in the sense of a location or a dot. Here are some examples:
* Puncture: To make a hole in something, usually with a sharp object.
* Punctual: Being on time, adhering to a schedule. (This word is related to the concept of "points" on a clock face, but it doesn't start with "punct-".)
* Punctilious: Paying careful attention to detail and formality.
If you are thinking of a specific word or concept related to "point" that you think starts with "punct," please provide more context.