Sorry for the late response.
Jim has mentioned some good solutions. Also, one that we have implemented is in our packages, we list the path to the installation source as, "\\%SITE%\RemoteShare\Apps\app1.exe".
Then, in the properties of the client there is an area which allows you to define a Site for the machine. In that Site field, we enter the name of the server at the local branch. i.e. (Serv1W2K3)
When the job is run against the client the token is replaced with the value in the "Site" field. So the final installation path would be, "\\Serv1W2K3\RemoteShare\Apps\app1.exe".
In the Advanced options for the package, make sure you select either "Copy files directly from the source the execute" or "Run directly from file source"
There is a SQL query that can be found in the Altiris KB that makes setting the Site field on all existing clients a lot easier. With your clients seperated into different groups based on geographical location, you enter the server name into the Site field for one client in each group. The query then copies that value to all other clients within the same group.
This may not work for you but I thought I'd trow it out there as an option.