Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
virtually [ˈvəːtjuəlɪ] adv (almost) факти́чески, практи́чески
it is virtually impossible э́то факти́чески or практи́чески невозмо́жно
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.