The standard valued CASE expression is supported. When dragging a Valued Case into a variable, the following tree element is created.
Variable Creation > Input > Variables: SQL Elements pane - Case > Valued
Which evaluates to:
CASE expression WHEN condition/expression THEN expression END
Columns and/or other expressions can be moved over the (empty) branches of the tree.
There are no special properties for the Valued Case function.
The ELSE expression is optional, and if not specified, the expression will return NULL if no WHEN conditions evaluate to TRUE. At least one WHEN/THEN condition is required with the CASE expression, and a test expression is also required with the valued form.