How put multiple Parameter using Variable in IN Clause in Sql Server

declare @val varchar(20)

declare @sql nvarchar(200)

set @val = '''A'',''B'',''C''' --Your Prameter of Program

print @val

Set @sql='select * from SomeTable where name in ('+@val+')'

--Print @sql

exec sp_executesql @Sql -- Is used to Execute Sql query