How to implement cachebusting / versioning for an external file called within a template

[bzcomputers]

At times I call external .css and .js within templates. I would like to able to use XenForo's built in cache busting for this. Without referencing PHP filemtime directly within a template what is the best way to go about this?

Sample css reference within template:

Code:

<link rel="stylesheet" href="https://www.mysite.com/styles/custom.css" type="text/css" />
How to implement cachebusting / versioning for an external file called within a template

free plugins
minecraft paid for free
mcmarket
mc-market
free minecraft paid plugins
free minecraft plugins
spigotmc
SpigotMC
aac free
ewg free
Minecraft Premium Plugins
ewg free download
litebans free
epicworldgenerator free
free schematics
leaked schematics minecraft
schematics
schematics leaked
schematics free
minecraft schematics free
paid minecraft schematics free
paid minecraft schematics for free
free cracked plugins
free cracked minecraft plugins
plugins
featherboard download
featherboard plugin download
antiaura download
xenforo leaked
xenforo for free
xenforo addons