Symbol names specified in filtering lists can include wild-card patterns.
The wild-card patterns recognized by ssget are the same as those recognized by the wcmatch function. When filtering for anonymous blocks, you must precede the * character with a reverse single quotation mark ( ` ), also known as an escape character, because the * is read by ssget as a wild-card character.
For example, you can retrieve an anonymous block named *U2 with the following:
(ssget "X" '((2 . "`*U2")))