how to call basic browser functions?

[BLElliott]

I think this is a very basic question, so feel free to direct me to a 
FAQ or other resource to go and get myself educated, if that's the best 
answer.

Can I perform web browser functions from a script, for example, doing 
file downloads, if I can construct the file URL within my script?  As an 
example, suppose there's a file I download periodically, but its URL 
changes with the current date.  If I can write a script that will 
automatically generate the URL, can it then go and fetch the file for me?

thanks in advance,
Bruce