Wildcard subdomains pointing each one to a folder with the same name as subdomain

Hello, nowadays I add a block for each subdomain like this:

server {
server_name instigado.hifolio.com;
root /home/hifolio/public_html/instigado;
include miolo.conf;
}

server {
server_name danca.hifolio.com;
root /home/hifolio/public_html/danca;
include miolo.conf;
}

server {
server_name smartgrids.hifolio.com;
root /home/hifolio/public_html/smartgrids;
include miolo.conf;
}


Is there some way of doing the same using wildcards, like using a regexp on $host variable or something like that?
Thank you very much.

Dimitre