Remove Alpha and special Characters from a string or REGEXP_REPLACE Or convert to number

Replace alpha bits to null value and convert to number


SELECT REGEXP_REPLACE('%%213213kjkj23213bjk123',
'([[:alpha:]])',
'') RESULT
FROM dual


Replace alpha numeric and Special character to null and convert to number


SELECT REGEXP_REPLACE('%%213213kjkj23213bjk123',
'([[:punct:]^[:alpha:]])',
'') RESULT
FROM dual


ex:

SELECT count(orgn.organization_id), to_number(trim(REGEXP_REPLACE(substr(trim(orgn.NAME), length(trim(orgn.NAME))-3+1),'([[:punct:]^[:alpha:]])',''))) org
                    FROM apps.hr_all_organization_units orgn
                    where type= 'FCLT'
                    group by to_number(trim(REGEXP_REPLACE(substr(trim(orgn.NAME), length(trim(orgn.NAME))-3+1),'([[:punct:]^[:alpha:]])','')))