Aggregate in SELECT query

Hi All,

Is it possible to manipulate(add, subtract,...) two fields belonging to two different tables in a SELECT query or JOIN statement.

Ex.

       SELECT 
         <TABLE1>~<FIELD1> 
         <TABLE1>~<FIELD2> 
         <TABLE2>~<FIELD1> 
         <TABLE1>~<FIELD2> 
       INTO TABLE
         <RESULT_TAB> 
       FROM 
          <TABLE1> 
        INNER JOIN 
          <TABLE2> 
        ON 
          <TABLE1>~<FIELD1> = <TABLE2>~<FIELD1>  ...

My problem is, while selecting can i add or subtract two fields say <TABLE1>_{<FIELD1> and <TABLE2>}<FIELD1>.

Regards,

Mustajab.