There is no standard way to do so, because in most of the cases it is a bad idea to do string manipulation in SQL...
However you can use CONCAT
] to do so easily (for a fixed list of columns):
declare @sep as nchar(1) = '$'
concat(col1, @sep, col2, @sep, col3, @sep, col4)
(you may need some casting, depending on the column data types)