How can I use a parameter to select a column?

[Pit927]

Hi!
How can I use an input parameter in the function to select a column?

Same as using ["NAME COLUMN"], then use a parameter: [parameter]
For example, in this case of combining columns:

When I introduce the parameter, I replace it within the [ ]

Because I know that if I put it in the editor as: ["parameter"] it works, but I wanted to use it as a variable for more fields..

Thank you.
All the best!

[Pit927]

Hi @lbendlin 
If I remove the square brackets the result is:

ID	FIELD	ID - FIELD
1	Black	1 - FIELD
2	Yellow	2 - FIELD
3	Orange	3 - FIELD
4	Blue	4 - FIELD
5	Green	5 - FIELD

I need this result:

ID	FIELD	ID - FIELD
1	Black	1 - Black
2	Yellow	2 - Yellow
3	Orange	3 - Orange
4	Blue	4 - Blue
5	Green	5 - Green

I need select the column with the name of the parameter. 

[lbendlin]

Read about Expression.Evaluate. Make sure to read the scope part carefully.

[Pit927]

It doesn't work for me. What I need is a toString of the parameter inside the brackets to search the column. Now it's looking for Field literally.

[lbendlin]

specify only the parameter name, remove the square brackets.