make temporary table

I have 2 problem,

i want execute a select command that table name is parametric and want save the result into temp table,to use from this table into another commands.but i dont konw how make temp table?

?=exec('select clm1,clm3,clm9 from '+@tbl1)

what is "with etc" command?and i can use 3"with etc"command in a query?