All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
If you were asking about donating the money of the voluntary Hajj to someone who is incapable of affording the Hajj expenses so that he would perform Hajj, you should know that he is not asked to perform Hajj as long as he in incapable. Allaah The Almighty Says (what means): {And [due] to Allaah from the people is a pilgrimage to the House - for whoever is able to find thereto a way.}[Quran 3:97] Giving money to such a person is a kind of charity and scholars said that Hajj is better than giving its amount of money as a charity unless there was a necessity. Shaykhul-Islam Ibn Taymiyyah said, "Voluntary Hajj is better than voluntary charity. However, if the person had poor relatives or if there were people who will be harmed if they did not get his charity, giving charity for them will be better. If the two acts were voluntary, Hajj will be better because it is a physical and financial act of worship."
Some scholars said that giving charity is better than performing voluntary Hajj. This was mentioned by Ahmad. Shaykh Ibn ‘Uthaymeen said that it is better to give money to another person so that he would perform obligatory Hajj than to perform voluntary Hajj. He was asked: "If someone paid the expenses of Hajj for someone who has not performed the obligatory Hajj, will he get the same reward as the person to whom he gave the money? Is this better than assigning someone to make Hajj on his behalf?
Shaykh ‘Uthaymeen said: "Yes. Allaah Willing, he will get the same reward of performing obligatory Hajj as the Prophet, sallallaahu ‘alayhi wa sallam, said: 'Whoever equips a Ghaazi (fighter) in the Way of Allaah is as if he has taken part in the fighting himself." Hajj is a kind of Jihaad and giving the poor person money to perform the obligatory Hajj is better than giving the money to someone to perform voluntary Hajj on his behalf. This is because he will help his fellow brother to take the reward of performing one of the pillars of Islam."
If you meant that you want to perform Hajj by yourself and grant the reward of this Hajj for an incapable person, this is impermissible as it is permissible only if the person is dead or physically unable to perform it.