Adding the IWAM/IUSR accounts to a security template

How do you add the IWAM_hostname and IUSR_hostname to a security
template to that it will work on another host? Do you have to set the
hostname to some type of variable? Ex.
IWAM_%hostname.

I am new to build templates, so I am curios since by default these
accounts have the hostname of the local computer. I know how to add
them on a local computer an implement the template, but will the
template work on another machine with a different hostname.

Thanks in advance,

Alex