The phrase "a point upon" is correct and usable in written English.
It can be used in contexts where you are referring to a specific location or moment in time, often in a more formal or literary style.
Example: "The discussion reached a point upon which all members could agree."
Alternatives: "a point at" or "a point in".
In addition, not to put too fine a point upon it, he had to be bribed.
And it is, not to put too fine a point upon the matter, obscene.
Not to put too fine a point upon it, that is what the Treasury thought when appointing Carney.
Not to put too fine a point upon it, Osborne and his colleagues have thought for some time that the Bank needs a good shakeup, and that if at all possible the job should go to an outsider.
The Exxon subpoena may nominally have been about misled investors, but it was really about then-Attorney General Eric Schneiderman acting as a champion in the fight against global warming, a point upon which I elaborate in my column of two years ago.
May's 1881 treatise reported that "[w]hether materiality is a question of law for the court or of fact for a jury, is a point upon which the authorities are about equally divided". J. May, Law of Crimes §188, p. 205.
In addition, the magnetic field at a point depends upon how far the point is from the current element.
The temperature rise has slowed from 0.12C per decade since 1951 to 0.05C per decade in the past 15 years – a point seized upon by climate sceptics to discredit climate science.
Many young people just leaving school or college have little chance of finding decent work.At the factory gate the mood is tense, a point seized upon by his political adversaries.
But, still, it is a point resting upon legitimacy.
Our method makes no correction for the degree to which tuberculosis HIV prevalence fails to approximate tuberculosis HIV incidence, a point elaborated upon in the concluding section.
