Where to place external subroutine files?

I'm trying to implement some gcode in external subroutines.

The subroutines work if tested within the same file as the calling code.

I export them to their own file (triple checking formatting and using the right brackets and gt lt signs etc) and load the main (calling) file into Axis and it is ignored.

I'm wondering if i'm storing them in the wrong location on the file system. currently both the main file and the called file are in the same directory which is a storage folder under my home.

I can't tell you how many times I've read that exact chunk and never saw the PROGRAM_PREFIX part.

I'll go hide in the corner now.