Proper Format for an .htaccess Alias

I'm trying to set up an alias/directory remap in the .htaccess file.

I tried

Alias home/domain.com/asdf home/domain.com
and
Alias root/domain.com/asdf root/domain.com

And both return an internal server error. What is the best way to do this?

I know this can be done in the panel, but I"m going to have hundreds of these and would like to be able to update via script.

It is my understanding that "alias" is an httpd.conf setting that cannot be used in an .htaccess file on shared hosting at Dreamhost.

The control panel facilitates alias by writing the appropriate entry to httpd.conf for your instance of Apache. You *can* use apache rewrite rules to accomplish most of the same thing.

--rlparker