Is it possible to achive 100% descriptive programming in TestComplte.?? For the desktop application

No. (Assuming 'Descriptive Programming' means referencing all tested objects via NameMapping/Aliases only.)

Just because your application uses (third-party) controls like grids/lists/combos/etc. that require custom access to their elements and the location of these elements is not static. (E.g.: "Locate the 'US $' cell in the Currencies table/grid and click Edit button in the right-most column to edit the exchange rate.")