Here's code to run for 20 seconds. I don't know what particular export you're seeking, but if you can figure out the keystrokes to pass to SendKeys, you'll be golden.
Code:
Option Explicit
const milliseconds=20000
dim WSH
set WSH=WScript.CreateObject("WScript.Shell")
WSH.Run "netstumbler.exe"
WScript.Sleep milliseconds
WSH.AppActivate "Network Stumbler"
WSH.SendKeys "%{F4}" 'Alt+F4 to exit