Tracking 2018 World Cup for betting [Hjelp til en tippekupong]

[Trond64]

Hello.
(Google translate - hope it's understandable)
Have a few, hopefully small, problems I hope someone can help me with.

Have made a sheet for betting soccer WC2018. After initial rounds, players must predict the correct group position. The yellow fields must be filled out:
2018-05-22_1412.png
1:
Correct positition in group. I have, on the yellow fields, used data validation with list retrieved from the groups above. That is, filling in Group A, the list is taken from B67: B70.
Is there any possibility to prevent double registration? As I have done, for example, Russland (Russia) could be registered in all four places in the group.

2:
When filling out the groups, the matches for eight-finals will appear. For example, the first match, C1 will be replaced by cell D74 with the following formula: = IF (D74 = ""; "C1"; D74) and D2 with corresponding = IF (E75 = ""; "D2"; E75).
This works, but my problem is that for the yellow box G81 I would like a drop-down menu where the two teams (C1 and D2) can be selected. Is it possibe?
(Now I'll fix it by manually typing the text, but it can cause problems if someone writes incorrectly).

[Kaper]

May be you could analyze how this piece: https://eexcel.co.uk/euro-cup-2016-e...atch-schedule/ works, and use this knowledge in your spreadsheet