Excel - How do I get the n-th text within a range of cells if some cells within the range are empty?

I am currently working on an excel file where I would love to get your help with a formula.

Milestone payments which only apply in some cases

Situation: The column "cash-inflows" is pre-filled with all possible milestones. In the future, users should only type in the values if an inflow was recorded for the corresponding milestone. This means that payments for many milestones will remain empty.

Goal: In a separate table, I want to create an overview of milestones which apply to the specific project. I would therefore love to have a formula which identifies the first milestone where a payment has been recorded (i.e. the sum of inflows unequals zero). As I would like to copy the formula, it should, as a next step, identify if the table already contains the first (second, third etc.) milestone and hence spit out the second (third, fourth etc.) milestone.

Which formula should I use?

I have already tried

INDEX('Cash-inflows'!B29:B58;MATCH(TRUE;ISTEXT('Cash-inflows'!B29:B58);0))

This spits out the first milestone. For subsequent cells I have tried

=INDEX('Cash-inflows'!$B$29:$B$58;SMALL(IF('Cash-inflows'!$B$29:$B$58=C8;ROW('Cash-inflows'!$B$29:$FE$58)-MIN(ROW('Cash-inflows'!$B$29:$FE$58))+3);1))

whereby column B always refers to a helping column which only spits out the milestone if the sum of payments unequals zero. The problem with the second formula is that I would still have to adjust the "+3" manually. I would therefore gain nothing.

With Microsoft 365 you could use: =TAKE(TOCOL('Cash-inflows'!$B$29:$B$58,1),-1)
Where TOCOL with condition 1 filters out the blanks and TAKE with argument -1 takes the first from the bottom of the TOCOL array (equals the last non-empty value).

In older Excel you could use:
INDEX(ROW(2:2),MAX(IF('Cash-inflows'!$B$29:$B$58<>"",COLUMN('Cash-inflows'!$B$29:$B$58)))) entered with ctrl+shift+enter