Dynamic sql is not working in restore database version 2008

Friends...

Os: win2k3

DB: sql server 2008

I am planning to restore the latest backup set from production to test db. i have to get the max position from the restore headeronly command to a variable and pass it to restore command.

i have written this query..but iam still facing some problem in executing this query.

declare @position1 as int

declare @tempsql1 nvarchar(max) 

set @tempsql1='RESTORE HEADERONLY FROM DISK = ''D:\DailyDBbackup\ciet.BAK''';

execute(@tempsql1); ======== upto this statement working fine...

SELECT @position1 = MAX(position) FROM @tempsql1 WHERE BackupType = 1 AND BackupName = 'ciet-Full Database Backup';

'Here @tempsql1 is not getting the value from the above variable. i am getting the error as Must declare the table variable "@tempsql1".

RESTORE DATABASE ciet FROM DISK = 'D:\DailyDBbackup\ciet.BAK'
WITH  FILE = @position1;

can anybody correct this error?

thanks & regards