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