ABSTRACT: Our 86 GHz (v=1, J=2->1) SiO maser survey with the 30-m IRAM telescope of a sample of late-type stars in the inner Galaxy has doubled the number of stellar (mostly AGB stars) line-of-sight velocities known at low latitude (|b|<0.5). This large sample of stars allows us to isolate two kinematic populations: one associated with the gaseous nuclear disk and the other with the Galactic bulge and/or inner Galactic disk. We propose to obtain near infrared spectra of these two kinematiclly selectred groups. We will perform a comparative analysis of their photospheric absorption features to search for clues to their formation history. In particular, we will address the question of how the stellar nuclear disk relates to the Bulge and inner Galactic disk.