New module, how to insert .tpl s='something' into language packs

[PrestaHeroes USA]

Unsure how we add new phrases used by our .tpl to the language packs installed on the ps site (1.4+) when install module is requested. For example we have new/changed .tpl tags

 

s='something something'

 

We want to be able to update the language packs during module install, i.e. insert appropriate translations for s= 'something something' into the proper language packs (if they are installed).

 

I've seen several posts asking how to do this, but no definitive answers.

 

Thanks in advance for your review and comment.