Cursor Select And Variables

I have problems to place my variable into the select statement.

DECLARE @DB_NAME varchar(64)
DECLARE MR_ReqPro_DB_cursor CURSOR FOR
select name from dbo.sysdatabases where name like '%MR_req%'
OPEN MR_ReqPro_DB_cursor
FETCH NEXT FROM MR_ReqPro_DB_cursor
INTO @DB_NAME

WHILE @@FETCH_STATUS = 0
BEGIN
print @DB_NAME; --works fine

Select NAME, FILEDIRECTORY FROM @DB_NAME.MR_ReqPro.RQDOCUMENTS WHERE (FILEDIRECTORY LIKE '%\%');

FETCH NEXT FROM MR_ReqPro_DB_cursor INTO @DB_NAME
END
CLOSE MR_ReqPro_DB_cursor
DEALLOCATE MR_ReqPro_DB_cursor

GO

How could i use a variable like @DB_Name in my select ?