TSQL select into Temp table from dynamic sql

declare @sql varchar(100);

declare @tablename as varchar(100);

select @tablename = 'your_table_name';

create table #tmp 
    (col1 int, col2 int, col3 int);

set @sql = 'select aa, bb, cc from ' + @tablename;

insert into #tmp(col1, col2, col3) exec( @sql );

select * from #tmp;

A working example.

DECLARE @TableName AS VARCHAR(100)
SELECT @TableName = 'YourTableName'

EXECUTE ('SELECT * INTO #TEMP  FROM ' + @TableName +'; SELECT * FROM #TEMP;')

Second solution with accessible temp table

DECLARE @TableName AS VARCHAR(100)
SELECT @TableName = 'YOUR_TABLE_NAME'

EXECUTE ('CREATE VIEW vTemp AS
        SELECT *
        FROM ' + @TableName)
SELECT * INTO #TEMP  FROM vTemp 

--DROP THE VIEW HERE      
DROP VIEW vTemp

/*START USING TEMP TABLE
************************/
--EX:
SELECT * FROM #TEMP


--DROP YOUR TEMP TABLE HERE
DROP TABLE #TEMP