If you store the shortcuts in the database as a string, you can split the string based on + character and then map each element to proper enumeration in
Keys[
^].
As you have already done, use the KeyPreview property set to true and check for shortcuts in proper form event.
However, I feel that storing the shortcuts as text in the database is a bit awkward. Could you should consider a different kind of table design, for example shortcut key and 'boolean' columns for ALT, SHIFT etc or even use the Keys enumerations, possibly as rows instead of columns....