How to match format of matching value? *Google Sheets

How to match format of matching value? *Google Sheets
https://i.sstatic.net/xeZmS.png

If I understand your question, I think I have an answer for you. See sample sheet here: https://docs.google.com/spreadsheets/d/1QhED3qsoUiX0Km8R86Rg6kHdKdjwQW0uhHZeOd40Sy4/edit?usp=sharing

Note that this currently requires one formula for each of your due date columns, but these are easily dragged across, from D10, for as many columns as you need. There may be a way to combine them as one, but I haven't figured that out yet.

This conditional formatting rule's formula is applied to include D10:D and across as many columns as you need - D10:I18 in this sample sheet.

=arrayformula(index($A$2:$C$18,match(D$9&D10,$A$2:$A$18&$B$2:$B$18,0),3))

which combines the date and the item name, finds them in the initial data, and sees whether the Paid checkbox is ticked. If yes, it formats the text as "strikethrough". For clarity, I've also formatted the cell to gray, but this is easily removed, in the formatting options for that conditional formatting rule.

REFERENCE:

INDEX

ARRAYFORMULA

Conditional Formatting rules