Regex (regular expressions) are used for testing a string for a pattern 
match of some sort (as well as extracting portions of the string), for 
instance a phone number.  Paradox picture  does pattern matching as well 
but it is on the user interface side.
Since mysql isn't about data input (it doesn't have a user interface for 
everyday users), it isn't going to have anything to test the data as it 
is input.  Whatever you are using on the user front end would have to do 
that.
Mysql does have regular expressions 
(https://dev.mysql.com/doc/refman/8.0/en/regexp.html) and there are 
plenty of discussions on validating data for different formats or 
extracting data based on the expression.

n.b. Paradox advmatch is based on regular expressions.
--
Mark B.

On 2/16/2022 6:31 PM, PhilipTdotcom wrote:
> How can I replicate Paradox's "picture string" functionality in SQL?
> 
> Specifically, I'm using MySQL Workbench... looks like there's some way to
> use a "language" called regex, perhaps in conjuction with the "Default/Expression"
> column when creating a field in a table, but I can't figure out how it works
> (and I apparently am unable to formulate a Google search that will show me
> what I need).
> 
> Any help would be much appreciated!
> 
> PT@PhilipT.com
>