Extract and reformat date

This should be straightforward, I just don't understand the syntax of the scripting language yet...

In the field "Comments", I have text like this...

"Debuted on 12/25/1980 on the Top 100 charts."

I want to extract the date and reformat it in the Date field like: 1980/12/25.

So it's a question of finding the first, second, and third slashes, something like:

Date = "(2 positions left of first /), then a "/", (between the first and second /), then another "/", (then 4 positions to the right of the last /)"

So how do I write that line?

Assuming the comment tagfield always contains a valid date string of format mm/dd/yyyy, then you may use the following actionsgroup to isolate and reformat the date string (tagfield DATE is saved as YEAR).

Begin Actionsgroup TEST

Action #1
Actiontype 5: Format tag field
Field: DATE
Formatstring: %comment%

Action #2
Actiontype 4: Replace with regular expression
Field: DATE
Regular expression: ^.+?(\d{2})/(\d{2})/(\d{4}).+?$
Replace matches with: $3/$1/$2

[_] case sensitive comparison

End Actionsgroup TEST (2 Actions)