From: Rabbi Moshe Sofer
To: Rabbi Tzvi Hersh Lehren
A wealthy man's will established an endowment requiring a promising student to study Torah abroad, but after a year and a half the yeshiva declined and the student returned home. The Chasam Sofer rules that the guardians may not fundamentally alter the testator's instructions, as a year and a half does not satisfy the intended duration of study; however, as a temporary measure the current student may retain his allocation and share it with the orphan, while future recipients must commit in advance to studying abroad for a specified period.
Source: Shu"t Chasam Sofer CM §9