Vladimir_02, примерно так
Код:

;!@Install@!UTF-8!
SetEnvironment="Name=test.txt"
RunProgram="%%P:hidcon:cmd /с for /f \"delims=\" %a in ('dir /b /s \"%%T\\%Name%\"') do start \"%a\""
GUIFlags="2+4+8+16+32+2048+4096"
GUIMode="1"
MiscFlags="4"
;!@InstallEnd@!