I am not sure if this can be done in excel but lets see...

Assume the following in a 3 column table:

Cell A1: Concrete
Cell A2: Excavation
Cell A3: Footings
Cell A4: Formwork

...

A10: Steel Column
A11: Wood Frame


Cell B10: =a1 & ", " & a2 & ", " & a3 (which displays Concrete, Excavation, Footings)
Cell B11 =a1 & ", " & a3 & ", " & a4 (which displays Concrete, Footings, Formwork)


Here is my question...

Can cell C1 scan the contents of a range of cells in column B, which has similar formulas, and display a cell's content from column A, which used A1 in its formula? (if cell B10 used A1, then C1 should display content of A10. If also B11 used A1, then C1 should also display content of A11 and so on... so in this case, C1 will display "Steel Column, Wood Frame")

(think of this as a simple schedule program, where column A has activity names, B has predecessors, and C has successors. I want C (successor) to display automatically which other activities mentioned that particular row as a predecessor)