My NSIS installer creates Start Menu links to run and uninstall my application.
Using NSIS, how do I create StartMenu shortcut to open a folder in Windows Explorer?
the same as any other shortcut
CreateShortcut "$smprograms\my app\my shortcut.lnk" "c:\path\to\folder"
this is explorer 99% of the time, and its really what you want, but if you want to force explorer
CreateShortcut "$smprograms\my app\my shortcut.lnk" "$windir\explorer.exe" '/e,"c:\path\to\folder"'
but that shortcut will have the wrong icon etc