Blender Virtual mirror (Modifier) help?

I added a cube, subdivided it and deleted the right sides polygons and made a virtual mirror for box modelling. Now, Here’s my question. is it possible so to make it that if you do a scale x it will scale towards the mirror? Not do that?

I tried to keep this post simple, and pictures are better than words ;).

Yes, just don’t select all the verts, leave the ones that interface with the mirror unselected and scale only those around them.