comparing two Spearman's rho coefficients

I'm looking to compare two Spearman's rho correlation coefficients
(asking whether correlations between a pair of
non-normally-distributed variables are different between two different
subject groups). I know this is possible with Pearson's r using the
method described here:
http://www.fon.hum.uva.nl/Service/Statistics/Two_Correlations.html
but I'm not sure if there's a problem with extending the method to
Spearman's rho.

Thanks for any advice or pointers.

Chris
.