Redirect wp-admin to subfolder

I have on root installation of wp and one sub folder installation of wp, i had edit the htacces and index of the root installation to show in my domain the sub folder installation of wp, so when i write my domain, its show the sub folder wp installation instead the root one.
All works fine but i have one problem, when i write domain/wp-admin instead of open the sub folder wp-admin page, i continue to open the root wp-admin page, and to access the sub folder wp-admin page, i need to write domain/subfolder/wp-admin.
So how i can redirect this one?