La. Civ. Code art. 1572
Testamentary dispositions committed to the choice of a third person are null, except as expressly provided by law. A testator may delegate to his executor the authority to allocate specific assets to satisfy a legacy expressed in terms of a value or a quantum, including a fractional share.
The testator may expressly delegate to his executor the authority to allocate a legacy to one or more entities or trustees of trusts organized for educational, charitable, religious, or other philanthropic purposes. The entities or trusts may be designated by the testator or, when authorized to do so, by the executor in his discretion. In addition, the testator may expressly delegate to his executor the authority to impose conditions on those legacies.
La. C.C. § 1572