Short answer. Yes. A testator may entrust to a third person the distribution of sums of money left in general to specified classes or causes, including the designation of which persons or institutions actually receive it — so leaving a fund for a third person to distribute among deserving students fits within this rule.
What the law says
The testator may entrust to a third person the distribution of specific property or sums of money that he may leave in general to specified classes or causes, and also the designation of the persons, institutions or establishments to which such property or sums are to be given or applied.
Civil Code, Article 786 — A Narrow Exception for Charitable Classes. Read the full provision →
The two things you may delegate
This article lets a testator hand a third person two related tasks: distributing property or money left in general to a specified class or cause, and designating the actual persons, institutions, or establishments that will receive it. In your scenario, leaving a sum "for deserving students or scholars" identifies the class, and the third person you name can then be trusted to pick which individual students or scholars actually benefit and how the money is divided among them.
Why this is treated differently from delegating validity itself
This provision works because you, the testator, have already fixed the essential decision — that the money goes to the class of deserving students or scholars — and left only the mechanical, discretionary task of choosing individuals within that class to the third person. That is different from letting someone else decide whether your gift takes effect at all, which the law treats as an impermissible delegation. Here, the disposition itself is already operative and defined; the third person is filling in details the testator deliberately left open.
What still needs to be clear in your will
For this delegation to work as intended, the will should specify the class or cause the money is meant to benefit — here, deserving students or scholars — since that class is what the testator's own intent fixes, while the choice of individuals within it is what gets delegated. A description too vague to identify any real class or cause could raise its own separate problems, which this provision does not address; it assumes the class or cause itself is adequately specified in the will.
The scope: specific property or sums, general classes or causes
The article speaks of specific property or sums of money left in general to a class or cause — a combination that fits a scholarship-style gift particularly well. The property or amount you leave can be precisely identified, even while the beneficiaries are described only generally as a class such as deserving students or scholars, with the third person filling in exactly who from within that class actually receives it and how the fund is divided among them.