Hi!
maybe it is very simple... i don't know...
so

there are known the distances between two cities, which i write in table
example:
A B C
1 City1 City2 Distance
2 A B 1
3 A C 2
4 B C 3
5 C A 2
6 D A 4
etc.
This can be the source.

And table with city names only.
A B C
1 City1 City2 Distance
2 A B ?formula? (the source is above)
3 C A
4 C A
5 D A
6 D A
7 A B
8 A B
9 B C
10 B C
.... sooo long.
Is there any formula to write in the column Distance to fill in with
correspending distance from A to B and D to A etc.?
I use filters, but this takes very very long.
I will appreciate any advise!