Column-dependent output of a content element

It often happens that you want to define the output of e.g. headings or links, i.e. content elements, differently for each column. The following query shows this using the example of a different CSS class for each column for links:

temp.tt_content.text < tt_content.text.20
tt_content.text.20 >
tt_content.text.20 = CASE
tt_content.text.20 {
key.field=colPos
## Column 1 
1 < temp.tt_content.text
1.parseFunc.tags.link.typolink.ATagParams=class="class2"
## Column 2
2 < temp.tt_content.text
2.parseFunc.tags.link.typolink.ATagParams=class="class3"
## Column 3
3 < temp.tt_content.text
3.parseFunc.tags.link.typolink.ATagParams=class="class4"
## all columns not defined above
default < temp.tt_content.text 
default.parseFunc.tags.link.typolink.ATagParams=class="class1"
}