Try this, uncomment the EXEC statement.

DECLARE @SQLTemplate NVARCHAR(MAX)
        , @SQLCmd NVARCHAR(MAX)
        ,...

We have SQL Server 2008 R2 and SQL Server 2012 in production but I am posting it...

@echo off
set DB_NAME=SUPPORT_DB
set BK_FILE=C:\SQLBACKUP\Monday\%DB_NAME%.bak
set DB_HOSTNAME=192.168.50.5 (local-machine)
echo.
echo.
echo Backing...