normal scores test

Hello,

I need help in performing a Van_der_Waerden normal scores test in R. I 
have two arrays of scores(final on therapy scores from drug and placebo) and 
want to use the normal scores procdeure to test for significance. 
(observations are unequal in number - due to dropouts). Could you please help 
me out with the coding or let me know if there is a package that can be used 
(for example, suppdist etc.)

Thanks in advance

Regards

~S