R help - Apr 2008 - polytomous or multinomial regression for matched data

Hi,

I've been trying to find a program that will run a multinomial 
conditional regression on k:m matched data.  Does anyone know of a 
package in R or another package that will allow this?  It's not obvious 
that multinom within nnet or VGAM will allow matched sets.  I've used a 
program (mcl) in STATA and SAS, but my parameter estimates from both 
packages do not match--can't figure out why, but I think it's because we
have k:m matched sets.

Any help is appreciated.

Best,
Sara