Hi. Here is how you can use Easy Grin extension to snap your objects to a grid and make sure they are moving or deployed in certain coordinates.

In my example (a Bomberman clone game) I need to make sure each bomb is dropped in grid coordinates (64x64) even if the character is in between the grid lines.
All you need to do is:
On the even when you deploy the bomb
add the following to your BOMB object
Set X position
----> In the set position dialog choose --> Retrieve data from an object --> choose your EasyGrid object --> Position --> Snap --> Snap X co-ordinate to Grid
----> As a value to the snap position click on Retrieve data from an object --> choose your Bomb object --> Position --> X Coordinate)

Then do the same with Y coordinate.

When you done, every time you deploy a bomb it will be snapped to the nearest Grid in your EasyGrid object.

hope it helped,
Please let me know if you have questions.