Custom weldment profile- Locate profile snaps

Hi all,

   I have been building a library of custom weldment profiles and it is going fine, however, I am wondering if there is a way to insert
"locate profile" snaps in the profile to assist in construction.
When I insert the profile it will only locate to the corners of the profile, not the centre of the edges.

Thanks in advance.

        Brad

SolidworksWeldments