Combine multiple text cells if value exists in other cells

Trying to help out with a form, cant seem to figure out how to combine multiple long text cells. Using if errors out stating that it cant handle more than 255 characters. Currently copying to another cell with multiple if's then concatenating to another cell, but this seems cumbersome. Tried to figure out vlookup but I cannot make it work. Any suggestions?

A simplified picture looks like this:

info selection
1 text1 x
2 text2
3 text3 x
4 text4 x
5
6 text1
text3
text4
7

Welcome to the forum, far better if you describe the witth sample workbook with before and after scenario, maybe it can attract the solver to figure it out the problem faster

Regards
Azumi

Here is one sheet of this workbook. If you place an X in the fields of columns d through j then the comments of column j combine and appear in c24. If its too difficult to copy comments, that same text can be placed in different cells, as long as the result is the same.