You can, but the window needs to have a unique class/name/title/id or some such that you can refer to.
Start Compiz settings:
% ccsm
Select the "Place Windows" plugin
Make sure it is enabled
Select the "Fixed Window Placement" tab
Then click on "New" under "Windows with fixed positions".
Now you need to specify which windows have what fixed positions. Click on the "+" sign to bring up a window selection dialog, this will allow you to specify the window by class/title/etc.. You can choose one of the types and grab the window to see what it's value is to see if it's something unique you can use for placement. You can add multiple conditions and thereby end up with interesting combinations such as:
(class=myterminal) & title=one
Then specify your X and Y positions, save it and close the settings manager. The next time you place a window that fits the definition you've specified, it should place it in the appropriate location (you may need to 'compiz --replace' though I doubt it).