Character field updation help required

[ksr]

I have a Cutomer Table having Customer Ids as "123 J","342-J","786","876/J","453 JAL". I want to update this Table and all other Tables wherever the pre-updated value of "CustomerId" exists in the Database with only the Numeric portion of CustomerId concatenated with 3 character code like "JAL". The updation should only take in those cases wherever the character "J" or " " exist in the field. Incase of any other character than "J" or " ", the field should not be updated. Special characters like "/","-","*" need to be excluded.
For Example :
123 J should be updated with 123JAL
342-J should be updated with 342JAL
786J* should be updated with 786JAL
2607 should be updated with 2607JAL
876/J should be updated with 876JAL
952 N should not be updated
1002KR should not be updated
After updation of Customer field, the same process needs to be followed in all other Tables where the Customerid value exist. The names of such tables need to be found out by using an SQL Query. Before updation of all such tables, the enabled constraints need to be disabled. These need to be enabled after the completion of above updation process. Kindly let me know the steps along-with the SQL Scripts that need to be executed to accomplish the above updation. Thanks in advance, for anyone helping me out with the above.