You can use GetEXP/GetAAEXP and SetEXP.
Code:
my $currentaaexp = $client->GetAAEXP();
my $currentregularexp = $client->GetEXP();
my $aaexptogive = 1000;
$client->SetEXP($currentregularexp,($currentaaexp+$aaexptogive));
Did unnecessary declaration to show you what's going on but:
Code:
$client->SetEXP($client->GetEXP(),($client->GetAAEXP()+1000));
Would be less code.