concatenate text to range of text cells in another column

Since you're creating a new column of text, my earlier example should suffice, no?

It's just a matter of concatenating (using '&') the preamble of the URL, the contents of the product ID cell, and the rel/target parameters.

The only gotcha is that you're looking for quotes inside the result - to do that you need to double-quote so that Numbers knows to substitute a literal quote character.

Here's an example:

Column A has a series of product SKUs

Set the formula in cell B2 to:

="<br><A HREF=""https://site.dom/product/"&A2&""" rel=""noopener"" target=""_blank"">"

then fill down column B to fill out the table:

Append the text in-place?

There's no way to automatically append a text value to a range of cells.

I can only think of two paths forward:

Use scripting (e.g. a script that calculates the amended text and updates the cell values).

Create a new temporary column that concatenates the existing column with the required text, then copy that column's values back to the source.

By this, assuming your current data is in column B, set the formula in C2 to:

=B2&"text to append"

you can then fill this formula down the column to calculate the range of values.

Then select the cells in Column C, copy them, then select Column B and select Edit -> Paste Formula Results

This will copy the value (not the formula) from column C into column B, which should do what you need.