SELECT
COUNT(`id`) AS `am`,
(SELECT `res` FROM `table1` WHERE `id_com` = '100' AND `idus` = '1' LIMIT 1 ) AS `my_res`
FROM `table1`
WHERE
`id_com` = '100' AND
`res` > (SELECT `res` FROM `table1` WHERE `id_com` = '100' AND `idus` = '1' LIMIT 1 )
LIMIT 1