Is it permissible to give out the vowed money through another person in the country for which the vow was made, especially if the one who made the vow does not know the poor in his current country and will hand over the money to the agent upon meeting?

It is permissible to appoint someone to fulfill a vow on your behalf in your home country, as deputyship is allowed in matters of vows, especially in purely financial rights such as zakat (definition), charities, and expiations. This applies whether the principal is capable of performing it himself or not, because the fulfillment is achieved by the act of the deputy. It is also permissible to transfer it to another country, and there is no objection to borrowing the vow amount from the agent.