%s@{fileID: \\(213[0-9]*\\)@\\=\'{fileID: \'.(submatch(1)-1900)@
I am using this regex search and replace command in vim to subtract a constant fro
Another simple example:
Search: style="(.+?)"
Replace: css={css`$1`}
Useful for converting HTML to JSX with emotion/css!
For beginners, the accepted answer is correct, but a little terse if you're not that familiar with either VSC or Regex.
So, in case this is your first contact with either:
To find and modify text,
In the "Find" step, you can use regex with "capturing groups," e.g. I want to find (group1) and (group2), using parentheses.  This would find the same text as I want to find group1 and group2, but with the difference that you can then reference group1 and group2 in the next step: 
In the "Replace" step, you can refer to the capturing groups via $1, $2 etc, so you could change the sentence to I found $1 and $2  having a picnic, which would output I found group1 and group2 having a picnic.  
Notes:
Instead of just a string, anything inside or outside the () can be a regular expression.  
$0 refers to the whole match
Given a regular expression of (foobar) you can reference the first group using $1 and so on if you have more groups in the replace input field.
To augment Benjamin's answer with an example:
Find        Carrots(With)Dip(Are)Yummy
Replace     Bananas$1Mustard$2Gross
Result      BananasWithMustardAreGross
Anything in the parentheses can be a regular expression.
In my case $1 was not working, but $0 works fine for my purpose.
In this case I was trying to replace strings with the correct format to translate them in Laravel, I hope this could be useful to someone else because it took me a while to sort it out!
Search: (?<=<div>).*?(?=</div>)
Replace: {{ __('$0') }}
Regex Replace String for Laravel Translation
Just to add another example:
I was replacing src attr in img html tags, but i needed to replace only the src and keep any text between the img declaration and src attribute.
I used the find+replace tool (ctrl+h) as in the image: