Regarding Matanot L’Evyonim, we follow the ruling of the Mahari Asad (Siman 127), who states that the primary requirement is for the money to reach the poor person on Purim. If a person sets aside money now and it is delivered on Purim, he fulfills his obligation. Furthermore, if one gives it to a poor person beforehand but stipulates that they should only benefit from it on Purim, the obligation is also met. The Mahari adds that one can grant ownership (Zichuy) to the poor person through a third party; this is considered as if the poor person received it. Even if the money physically arrives after Purim, it is effective because the poor person legally acquired it beforehand, provided they are aware of it (Shraga HaMeir, Vol. 3, 112). This differs from the view of the Chida, who believed the money must be set aside specifically on the day of Purim itself.

Regarding Mishloach Manot, the Ba’er Heiteiv (Siman 695) expresses doubt whether sending them before Purim to arrive on the day is sufficient. According to the Manot Halevi, the essence of the Mitzvah is to increase peace and brotherhood on Purim itself. Therefore, the Aruch HaShulchan writes that the best way is to appoint a messenger on Purim day and reimburse them afterward, ensuring the entire act takes place on the day.

In summary: You may act on behalf of your father (may he live long and be well) for both Mishloach Manot and Matanot L’Evyonim. One can acquire a merit for another person even without their physical presence (Zakin L’adam Shelo Befanav). Certainly, this is his true will, and through your actions, he will merit to fulfill these Mitzvos on Purim as he desires.