Baptist Brack, later Ritter von Brack (1761–1835): entered service as common soldier in 1785, Unterlt. 1796, Oberlt, 1800, Stabskpt, then Hauptmann in 1806, pensioned in 1823. Campaigns: 1793, 1794, 1796, 1800, 1805, 1806/7, 1809, 1812.

Jakob von Pirchinger, (1778–1811): entered service as common soldier in 1795, Unterlt. 1800, Oberlt, 1806, Stabskpt. in July 1809. Campaigns: 1800, 1805, 1806/7, 1809.

Info from vol. I of Rudolf Ritter von Xylander, Geschichte des 1. Feldartillerie-Regiments Prinz–Regent Luitpold, Berlin, 1905, pages 432 and 436.
Highly recommend this thorough, archive–based regimental history for your research.