Try this for validation of A1
=AND(LEFT(A1,3)="ABC",ISNUMBER(MID(A1,4,6)+0),AND(CODE(MID(A1,ROW($10:$12),3))>=65,CODE(MID(A1,ROW($10:$12),3))<=90),OR(AND(CODE(MID(A1,ROW($13:$14),1))>=48,CODE(MID(A1,ROW($13:$14),1))<=57),AND(CODE(MID(A1,ROW($13:$14),1))>=65,CODE(MID(A1,ROW($13:$14),1))<=90)))