vscode regex sub match evaluate instead of concatenate?

Question

Test 300
Test 301
Test 302

I can use regex find to loop through these:

Test (3[0-9]*)

When I try replace with math it concatenates instead of evaluates?

Test $1-100

So, it becomes:

Test 300-100

Is it possible to evaluate instead of concatenate, so it becomes:

Test 200

Thanks.

Answer 1

There are more extensions that can do this now, including one I wrote Find and Transform.

With this keybinding:

{
  "key": "alt+m",                     // whatever keybinding you want
  "command": "findInCurrentFile",
  "args": {
    "find": "(?<=Test\\s)(3\\d\\d)",  // get 300+ in capture group 1
    "replace": "$${ return $1 - 100 }",      // subtract 100 from capture group 1
    "isRegex": true
  }
}