All perfect praise be to Allah the Lord of the Worlds. May His peace and blessings be upon our Prophet Mohammad and upon all his family and companions.
In order to answer this question, we have to take the following points into consideration:
1. Offering an Udhiyahha (Sacrifice offered during Eidul Adha) is a Sunnah for the able Muslim. In other words, the one who has extra money to buy an Udhiyah in addition to the needed money for spending on himself and his household on the Day of Eid (Eidul Adha) and the three days of Tashreeq (The days following the Eid Day). This is of course in light of that which suits their social and financial status, in addition to other considerations stipulated by the Muslim scholars. If one of the household members offers an Udhiyah, then this Sunnah is performed on his behalf and that of his household, but the reward is his alone in case he offered a sheep. Based on this, the poor person isn`t required to offer an Udhiyah.
2. It is permissible to appoint someone to slaughter the Udhiyah on one`s behalf in another country. However, it must be slaughtered in the time specified by Sharia and that is from after Eid prayer until the third day of Tashreeq. What counts, here, is the time of slaughtering, not the country of the person appointed to do that.
3. The poor must be given from the meat of the Udhiyah. In addition, it is permissible for the person offering it to eat from its meat and give to other Muslims. However, the more he gives to the poor the greater the reward. It is customary to give a third of the Udhiyah`s meat to charity, a third as a gift, and a third for one`s household. It is worth pointing out that it doesn`t matter whether the meat is distributed in the country of the person offering the Udhiyah or in another country.
4. It isn`t permissible to sell the meat of the Udhiyah; rather, it should be distributed as stated above and it isn`t permissible to give any portion of the Udhiyah to the butcher as payment for his work.
In conclusion, it is permissible to appoint someone to slaughter Udhiyah on one`s behalf in another country under the aforementioned conditions. And Allah The Almighty Knows Best.