Determine token value by comparing with token replaced string

Determine token value by comparing with token replaced string

I have a tokenised string like so;
var route = a/b/{firstId}/c/d/{nextId}
and I am wondering if it is possible with regex to get the value of
"firstId" via a second string with tokens already replaced.
Example, if I have a given string;
var partPath = a/b/33
I can do something like;
function getValueFromPath(path, route){
//regex stuff
return tokenValue; //Expected result 33
}
getValueFromPath(partPath, route);
Thank you,
C.