There is a Spanish language file already in the DT Register package. If the Spanish language is setup on your Joomla site, when you install DT Register, it will load the Spanish files. Then DT Reg will use the language files appropriate to the language set for the site.
Nathan is no longer affiliated with DTH since the recent acquisition. You can connect with him and get any type of Joomla website help at
www.JoomlaEmployee.com
.