[AndreT]

What you need is a simple loop that goes through all players and finds the administrators. Make it increment a variable so after the loop you know how many administrators were found. I'm going to assume you already have a command that finds admins.

pawn Code:

new foundAdmins;
foreach(Player, i) // or for(new i = 0; i != MAX_PLAYERS; i++) with a IsPlayerConnected check
{
    if(IsPlayerAdmin(i))
    {
        foundAdmins ++;
        // display admin name or whatever
    }
}
if(!foundAdmin)
{
    // No admins were found.
}