Single Representing Character
Policy Interest > Personal Power
Representing a character instead of a country at a GA-style committee is different from at a crisis committee. Since a GA committee asks for a resolution and the historical context rarely changes during the conference, your character's individual power matters much less in a GA committee.
Instead, your character's policy interest or political alignment is far more significant. This is what divides a room of delegates into blocs as in a committee of countries.
Less information available
Representing a character here is very similar to representing a country. One of the biggest differences is that you are likely to find much less information specific to your character than you would if you represent a country.
Look into related parties
If there is few information out there about your character, you can use your character's affiliation as proxy. Does your character work at certain organization/company? If yes, does that entity have a specific policy or political interest?
Personal history matters
Your character's past experience is a good source of information as well. It tells you how this person has come to where they are today, and a person's past would likely shape how they make decisions in the future.