mysql apply regexp_replace for whole column/multiple rows
Your idea was good, but you need STR_TO_DATE and you need the REGEXP_REPLACE in the SELECT not around a subselect


CREATE TABLE users_acts (exe_production varchar(100))




INSERT INTO users_acts VALUES ('blah blah blah 10.10.2020 (any date) blah blah')




SELECT 
    STR_TO_DATE(REGEXP_REPLACE(exe_production,
            '[^[0-9]{2}[.]{1}[0-9]{2}[.]{1}[0-9]{4}]',
            ''),'%d.%m. %Y')
FROM
    users_acts
            


| STR_TO_DATE(REGEXP_REPLACE(exe_production,
           '[^[0-9]{2}[.]{1}[0-9]{2}[.]{1}[0-9]{4}]',
           ''),'%d.%m. %Y') |
| :----------------------------------------------------------------------------------------------------------------------------- |
| 2020-10-10                                                                                                                     |


db&lt;&gt;fiddle here