A woman from western countries embraced Islam for a long time but her family are non-Muslims. A Muslim man from a Muslim country wants to marry her but he wants to conduct the marriage contract in his country with the consent of this woman. She does not have a guardian because her family are non-Muslims.
The questions to be asked are:
Is it possible to conduct the marriage contract in the country of the man while the woman remains in her original country, while he appoints a trustworthy brother to be her guardian with her consent for him to act as her guardian?
Is the marriage contract in this way valid with all the conditions of marriage: mentioning the dowry, the presence of two witnesses, consent and acceptance between both parties, and the presence of the guardian who is appointed to be a guardian for this woman by the party who wants to marry this woman?

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 is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.

If it is possible for you to conduct the marriage contract with her presence, either by going to her or bringing her to your country then this is good. Otherwise, there is no harm to conduct the marriage contract in your country but she must appoint someone authenticated by an Islamic centre to the effect that she appointed such and such person to marry her off to you or to any other person. In this case it is permissible for this man to conduct the marriage contract for her [to be her guardian]. 

Allaah Knows best.