How can I extract some part of the title from notes title ?

[radha1990kumari]

For example I have created a note named Lab-2_167 now the only number that will change is 2 i.e Lab-3_167, Lab-4_167 ,etc.

[radha1990kumari]

Heres the code

<%*
let re = new RegExp('Lab-(\\d+)_.*');
var myString = tp.file.title;
var match = re.exec(myString); 
var an="0"
if(match!=null)
an=match[1]
tR=an
%>