Difference Columns that subtract one row from another

Hi there,

Edited to include screenshots from Excel to demonstrate the problems:

Bit of a weird one, and might not be possible, but I have the following matrix viz:

The data is stored as below:

Table 1

I would to do the following in the matrix mentioned above, with columns for differences between certain forecast years and the latest actual year:

Is this at all possible? I've tried creating a calculated column in my table that calculcates scores for 2028 and scores for 2023 and minuses the former from the latter, (in order to just get the maths sorted out) but my matrix just looks like this instead:

Can anyone help? I'm totally stumped! I need those difference columns, if not as part of the matrix itself then at least as calculations on their own. Thank you!