Creating a list with entries from cells and manual entry too

[Rims]

I want to create a list with the values populated from some cells and also
include to the list
"None"
"All"

For the time being, I have asked the individuals to do a manual entry. And
have removed the Error Alert function. It works. But is there a way I can
append to the list of the cells additional values also?

Pls suggest.

Thanks!

 

[Bob Phillips]

What do you have already that populates that list?

 

[Rims]

I have a column with a list of steps in Column A
Step 1
Step 2
......
Step n

Adjacent to these columns, I have to enter whether they can go parallel or
not. And if parallel then with which step. The user can select the Step
number from the drop down. Some may not have any other step in parallel. For
them they need to write "None"

My output should be something like say:

Column A Column C (List)
Step 1 Step 7
Step 4 None
Step 8 Step 1