Help with cell manipulation

This is complicated for me because I am a novice MATLAB user, but it is important for me to be able to implement this into my code:

When all but the first or last values in a numeric cell within a cell, change from the value of -10 during the initial time step, to any other number during the next time step, add the difference between the two numbers adjacent to the numerical cell value that was just changed from -10.

call the initial time step cell: h0c

call the next time step cell: h1c

I posted a cell just as an example of its size and value.

Thank you in advance and I appreciate this community's help!