I use the Query Builder application to run 2 queries against the CMS database. The first query pulls all the users si_id based on the group si_id and the second query I use the user si_id's captured from the first query to pull the users full name and description information:
First Query:
SELECT SI_GROUP_MEMBERS, SI_NAME
FROM CI_SYSTEMOBJECTS
WHERE SI_PROGID ='CrystalEnterprise.UserGroup'
AND SI_ID = 627 <-- this is groups si_id
Second Query:
SELECT TOP 20000 SI_ID, SI_NAME, SI_USERFULLNAME, SI_DESCRIPTION
FROM CI_SYSTEMOBJECTS
WHERE SI_PROGID = 'CrystalEnterprise.User'
AND SI_ID IN ('219563',
'269398',
'219845', <-- these are user si_id's from first query
...
'212234')
Hope this helps...