Domain parking vs htaccess

I have several domain names and variations that I would like to point to a single website. Parking only seems to work with my host for a single domain but will call my host to find out for sure.

Cant I do the same thing with htaccess file?

Example:

abc123.com
abc123.net
abc123.org
def456.com
def456.net
def456.org

All should point to the abc123.com.

When I use the htaccess file I dtill get the error on each domain "No template file specified..." error.

thanks