>#define d_sum price*d_quantity as hello

I'm sorry. The sample code was too simplified. I need to use d_sum inside expressions in SELECT statement.
Real code where I tried your suggeston was

CREATE CURSOR invoice ( price N(12,2), quantity N(2), packing N(2))

#define d_quantity quantity*packing
#define d_sum price*d_quantity as hello

SELECT 2*d_sum+1000 FROM invoice

but this causes syntax error in select line