1) You need to have developer tab. For this File-->Options-->Customised ribbon--> check "on" the developer box.
2) Developer (Vb) will come in menus -->click on Devp--> Visual basic
3) VB window will open up--> Click on tools--> reference-->Tick "on" Visaul basic for applications and the two libraries-- Excel and Microsoft office .
4) Now load the ITR-4 file in excel --> validate each sheet and at last calculate tax
the generate XML and save XML
5) upload X M L and everify as usual.
Hope this helps. What i have told is for 2010 - but on similar lines do it for 2003
if it doesa not work I think u should down load 2007 version od XL.