@echo off
for /f "delims=" %%x in ('dir /od /a-d /b F:\Arma3\Arma3_Server\HC\*.rpt') do set recent=%%x
start "" "C:\Program Files (x86)\Notepad++\notepad++.exe" "F:\Arma3\Arma3_Server\HC\%recent%"

for /f "delims=" %%x in ('dir /od /a-d /b F:\Arma3\Arma3_Server\SC\*.rpt') do set recent=%%x
start "" "C:\Program Files (x86)\Notepad++\notepad++.exe" "F:\Arma3\Arma3_Server\SC\%recent%"