VS Code REST Client Extension: How to access nested response headers - http-headers

Question

I'm trying to access 'nested' headers with the REST Client extension for VS Code.
I defined a GET CSRF_Token request that stores the "Set-Cookie" header inside a #token_response variable.
However the header looks like this:
'csrftoken=aGHuGkRbApH3qAksHHR3uaOKG0eZsYne; expires=Wed, 22 Nov 2023 08:40:05 GMT; Max-Age=31449600; Path=/; SameSite=Lax'
I already tried to access it with something like:
#csrf_token = {{token_response.0.split(';').0.split('=').1}}
and
#csrf_token = {{token_response.//[0].//split(';')[0].//split('=')[1]}}
But this does not seem to be the correct syntax.
Also the documentation does not contain any hints on that yet, sadly.
Now my question is:
Is there a way to only extract the part of the header that contains the value of the "csrftoken" key?
And if so, how?
Here is my code:
# Get CSRF Token
# #name getToken
GET http://{{host}}/api/csrf_token
#token_response = {{getToken.response.headers.Set-Cookie}}
#csrf_token = {{token_response}}
######
# Edit existing xyz
PATCH http://{{host}}/api/xyz/1
content-type: application/json
x-csrftoken: {{csrf_token}}
origin: http://{{host}}
{
"name": "some name"
}
Thanks a lot in advance! :)