How it extracts CSV data from a sheet

ConvertExcelToCSVProcessor extracts CSV data with following rules:

As an example, the sheet shown below will be:

row ABCDEFG
1
2 xyz
3 1
42 3
5 4
6 567
7 8
8
9 9
10
11

converted to following CSV:

x,y,z
1,,
,3,
,,4
5,6,7
,,9