How To Automatically Replicate Remote Database Which Is Not Permanently Online

Dear group,

I have to replicate remote data to a SQL Server in the headquarter.
The data are on a site which does not have permanent online-connection
to the headquarter.

I have written a script which replicates the data and i want to set up
a process / batch on the headquarter-machine which roughly does the
following

1) Connect to the remote site
2) start replication script (in fact a stored procedure)
3) on success disconnect from the remote site

All this has to run automatically e.g. during nighttime.

Could someone please outline how i set up the connection and keep it
up during my database-action and how to automatically disconnect after
success of my replication script.

I'd be jolly grateful.

Thanks in advance and Greetings from Vienna

Uli