Dynamic SQL Create Table

The following dynamic SQL script works for creating a table on the fly but if I change the select @tmpTblNm = 'tmpABC' to select @tmpTblNm = '#tmpABC'
it will not create the temp table. Can anyone help on creating a temp table dynamiclly?

declare @tmpTblNm varchar(40),
@str varchar(1000)

select @tmpTblNm = 'tmpABC'
select @str = ''

-- Create a temp table to hold the current page of data
-- Add an ID column to track the current row
select @str = 'Create Table '+ @tmpTblNm +
' ( row_id int IDENTITY PRIMARY KEY,
customerID int,
customerName varchar(40),
address1 varchar(40),
city varchar(25) )'

exec (@str)