I am working on a spreadsheet that has to show links to other cells.
Sheet1 contains things like projectnames, timespans, etc.
Sheet2 contains project links.

So if project1.1 (in both sheets A2) has anything to do with project1.4 (in both sheets A5) and project3.7 (in both sheets A11) B2 will contain:

project1.4
project3.7

I would like to make things a lot more user friendly and easier to look up (or at least make it easy to see the impact of a project to other projects). Currently I am using comments to pull the data out of sheet2 and summup the linked projects in the mouseover, but it lacks timespan comparison, etc. Therefore I would like to be able to click e.g. project1.1 and see project 1.4 and project3.7 change color or highlight in some way.

I have been thinking of ways to use the backgroundcolor picker (also placed on this forum in a thread), but it just doesn't do the trick I'm afraid. Colors should also change back when deselecting project1.1. A mouseover option would fit as well, but I think a select option is more realistic.

Hopefully anybody has an idea if this is actually able to achieve in excel.
Thanks in advance.