I was hoping some other member would answer your thread, someone who knows a bit more about this then I do...
I am no expert, but I can tell you what I've got at home and works.
If you just wanted to go online with your laptop, you could just buy a USB modem...it plugs into your USB slot and via that you go online.
here's a link to some modems like that
Smartfren Modem & Router
but you want to go online with your laptop and HP (mobile phone), so you would need a wireless router..
on the same page but at the bottom of the page.
I have an older model router, but it works the same....insert sim, plug into a socket, scan for available wifi networks and connect to your router.
then go online...
as for the smartfren, you could by vouchers and add pulsa to your simcard from abroad...
But I think (not sure) roaming data will be expensive...here you can find a list of roamingpartners
Smartfren Layanan International Services
there are several packages available, be sure to pick the right one..
Hope it helps a bit.
friendly greetings, gilbert.