GO:0042281:   dolichyl pyrophosphate Man9GlcNAc2 alpha-1,3-glucosyltransferase activity
Catalysis of the addition of the first glucose residue to the lipid-linked oligosaccharide precursor for N-linked glycosylation; the transfer of glucose from dolichyl phosphate glucose (Dol-P-Glc) on to the lipid-linked oligosaccharide Man(9)GlcNAc(2)-PP-Dol.