Forcing a window to front does not work reliable. I tried several methods. It works sometimes and sometimes not (depending on how the window is hidden - minimized or not and stuff like this).
But you can use the "Flash Icon" plugin (shipped w/ LogExpert). It will cause the Taskbar icon to flash until the LogExpert-window is activated. I use this for the very same reason like you (waiting for an app startup finish). Activate it in the Highlight
Settings (check "Plugin").