there are a couple of ways to do this...
One way to do this is to place your entity on the map then right click the entity to get your edit menu on your left side over there is where you can make changes to your strength...
Now if your looking to go from static to dynamic then before placement of your entity on the map you want to press your y key this will change the color from green to red signifying that it went from dynamic to static (green = dynamic / red = static)
Now another way to make changes to your model is what I like to call hard coding this will change that model for all maps you work on untill you go back and make changes again... And thats going to your entity folder searching out the fpe file that Silent Thunder was describing and make your changes to that file....(Use notepad to open it up) and your entities can be found in this directory
C:\Program Files\The Game Creators\FPS Creator\Files\entitybank
I hope this has helped you some.... Also there is a stickie that may help you with scripting...here is the link
http://forum.thegamecreators.com/?m=forum_view&t=62366&b=23
Have you downloaded your CLiPs today.