Exporting estimates by group to Excel

Hello,

I am trying to export my estimations to Excel but I cannot export them by group. I can export the estimations of the panel but it doesn't work if I repeat the regression for each group. I tried the following command:

by group: ivreg2 variable (a b c=iv*), robust small first ffirst
estimates store vres
xml_tab vres, tstat append below sheet("d") stats(N N_g)
estimates drop *

Could someone help me to export the results to Excel please?