Does anyone know of a way to beautify/format the following code using a search/replace with a regular expression?

I'd like to format the code from this:

set north [lindex $string_list 0]
set east [lindex $string_list 1]
set elevation [lindex $string_list 2]
set arsenic [lindex $string_list 3]
set sulph [lindex $string_list 4]

to this:

set north [lindex $string_list 0]
set east [lindex $string_list 1]
set elevation [lindex $string_list 2]
set arsenic [lindex $string_list 3]
set sulph [lindex $string_list 4]

In other words, I'd like the different parts each line of the code block to line up vertically.

Thanks for any insight.