R help - Nov 2005 - Time-varying coefficients in Cox regression model

Dear All,

I was wondering whether there is an R/S implementation of Gray's method
(JASA 1992) for B-spline based time-varying coefficients in Cox regression
models.  I have searched the R help archive on the subject and although
there were several matches none seem to have address this point.

Thanks for any help.

-Christos Hatzis