How can i set more memory to use with dos-programe in xp sp2 ?

i made ms-dos programme by clipper 5.2 and use another programe for enterface arabic with code page 710 (nafitha), and now try to use other programe to convert text report to use with Excel and print it with excel mode , So I NEED to use MORE MEMORY , How Can Adjust Memory in win-xp sp2 to make it increase more when i use my programe'(s) , and more fast ?