Is it permissible to retract an oath phrased as "I vow to Allah that I will not do such and such" (meaning not to apply cream or moisturizer to the face except after consulting a specialized female doctor), and later offer expiation for the oath by feeding the poor in another country?

This vow is a vow of obstinacy (nadhir lajaj), which does not require fulfillment. It necessitates an expiation for an oath (kaffarat yamin) when the condition it was tied to occurs, which is the use of face cream and moisturizers.

There is no harm in transferring the expiation to another country, as it is valid in any country. However, the issue lies in delaying it. The majority of scholars hold that it is not permissible to delay the expiation for an oath, and that it becomes immediately obligatory upon breaking the oath. The Shafi'is, however, are of the opinion that it becomes obligatory at leisure, provided that breaking the oath was not an act of disobedience.

If sending the expiation to the poor in the questioner's country would result in its delay, then it is preferable to give it out where she lives, in order to expedite its disbursement.