You might want to search the details of the regiments noted below to see if you can find out more on this man.
https://familysearch.org/pal:/MM9.1.1/XPM7-62Z
name: Leonard Van Buren
event: Military
record type: Individual
state: New York
regiment: Stephen Schuyler's Regiment, Militia
nara publication title: Compiled Service Records of Soldiers Who Served in the American Army During the Revolutionary War
nara publication number: M881
nara roll number: 0756
https://familysearch.org/pal:/MM9.1.1/XPM4-D6V
name: Leonard V Beuren
event: Military
record type: Individual
state: New York
regiment: Henry K. Van Rensselaer's Regiment (Albany County), Militia
nara publication title: Compiled Service Records of Soldiers Who Served in the American Army During the Revolutionary War
nara publication number: M881
nara roll number: 0764