en­grec – Enu­mer­ate with lower- or up­per­case Greek let­ters

This pack­age pro­vides two macros \en­grec and \EnGrec to con­vert num­ber ar­gu­ments to lower case or up­per case greek let­ters. They have the syn­tax of \alph, i.e. \en­grec{a_counter}, \EnGrec{a_counter}.
Op­tions are pro­vided to work with the up­greek and fourier pack­ages.
Re­quires am­s­text.