En familie med Microsoft-regnearkprogramvare med verktøy for å analysere, kartlegge og formidle data.
That's totally different from your original post and it's all a bit confusing as your pictures don't match your question. You say column C1:C28 is marked blue and B1:B28 is marked green. But the picture shows that C9:C28 is green and R9:R28 is blue. And what do you expect to see in U11 in this example?
Anyway, you need a straight-forward XLOOKUP function. Perhaps like this in U11:
=XLOOKUP(F7, 'Sheet 1'!$C$9:$C$28, 'Sheet 1'!$B$9:$B$28, "")
This will return the number 2. OK?
I trust you can translate it to Norwegian Excel, if needed, yourself.