Inserting text if condition|Power Query|Excel Forum|My Online Training Hub

Hi,

Best to look at attached file for explanation of problem.
This is most likely ridiculously easy to figure out, but it escapes me, and I'd very much appreciate the help.

In short:

Two rows (or three, or four) contain identical serial numbers

One of the rows contains a cell with a value in it (in attach image it's LIJN 3) 

If the rows containing the identical serial numbers have no value in the cell, then the value from the row (with identical serial number) that DOES contain a value should be copied.

In Powerquery, I can add a index column 1; index column 0, merge queries and expand only relevant column, but this is not the right solution for this case I think.

I'd like to automate this... and it might well be that I have a number of files that do not have any "empty" cells..

Any help would be greatly appreciated,