Here is what I'd do:
Create a file with an editor of your choice, containing
netstat <here any options etc.>
and save it under a <convenient name>. Then
chmod 777 <convenient name>
Now comes the dichotomy
. System startup
is not KDE startup. For system startup you would have to call <convenient name> from the init files of the system (probably /etc/initrc or some such, right befor the call of kdm).
On your KDE desktop you would right-click -> new -> icon(?, choose something sensible), in the menu then popping up you have to assign a picture and more vital /path/to/your/<convenient name> command.
After saving, you should test it, output goes probably to console#0, i.e. press <Alt><Crtl><F1> to look for it, getting back to KDE is pressing <Alt><Crtl><F7>.
Alternatively you would have to look for something like a directory called autorun or some such in KDE (possibly KDE-Command center) and draw a link from your new icon to it, then the script starts right after KDE is up and running.
This is in part guesswork, try other reasonable venues and good luck