GetGuildInfo on a raid target

[bault]

I'm building an addon in wich i have to make sure a raid member is
in the same guild as the current player.

Is there any way I can do this WITHOUT having to target each raid member ?

Right now I'm using:

for i=1, GetNumRaidMembers(), 1 do
local name, rank, subgroup, level, class, fileName, zone, online = GetRaidRosterInfo(i);

local player_guild = GetGuildInfo("player");
ClearTarget();
TargetByName(name);
local raid_member_guild = GetGuildInfo("target");

if(player_guild == member_guild) then
........
end
end

But I'd like NOT to have to target the members to get their guild name.
(making so that range has no incidence on the mod operation)

Any pointers?