I Got Error Message

When I ran below stored procedure, I got error message.

create procedure pro_log
as
declare@Execution_String varchar(255),
@logfilevarchar(112)
select@logfile = 'server_name(F:)folder_namelog_name'+convert(varc har(8),getdate(),112)+'.log'
Select @Execution_String = '(F):Mssql7Binnisql -S server_name -U user_name -P password -d datebase_name -q"procedure_name" > ' + @logfile
Print @Execution_String
Execute master..xp_cmdshell @Execution_String
return
GO
exec pro_log

************************************************** *************************
Mssql7Binnisql was unexpected at this time.

(1 row(s) affected)
************************************************** *************************

Any body can please tell me what is meant by above error message?