I'm facing the following problem:

I have eleven columns of that represent product origins, sometimes the product is taken from one origin and sometimes it is taken from two origins. The columns have values in them that correspond to a fraction of how much is used of that origin. Example (only using 4 origins for ease of example):

```
NTH LGL MSV NIE
{1 0 0 0;
0.5 0 0.5 0;
0 1 0 0;}
```

The results that I want are then for the first row NTH, for the second row NTH-MSV and for the third row LGL.

I tried using the following formula, but I can't get excel to concatenate the empty cells or errors.

```
=CONCATENATE(IFERROR(OFFSET(AP1;0;IF(AQ4:BA4>0;COLUMN(AQ4:BA4)-COLUMN(AP4);""));""))
```

AQ1 to BA1 contain the product origins and the columns below contain the values (ranging from 0 to 1).