Hello, I want to bring in pictures and align and size them so that they sit
exactly between the borders of the B column

The left side of my shape should end up on the border between A and B and
the right side, on the border between B and C

Does that make sense?

The columns in the sheet may be different sizes so I'll need to include a
way of locating the left and right before positioning the picture. I can't
assume they'll always be the same.

Is this possible

Many thanks

M