How to carve up ZX Basic into different ORG values

[RandomiserUsr]

This might be asking a tricky thing to do but :-

GOAL :  
To have main.bas compile at 24576 as main.tap
with the ability to at runtime, call on the functions in the below separate files

Functions.bas compile at last address use above +1 as functions-Bank1.bin
** ZX Basic functions only 

textdata.bas compile at  last address use above +1 as textdata-Bank3.bin
** Mixture of ZX BASIC and ASM functions and data references.

picturedata.bas  compile at last address use above +1 as picturedata-Bank6.bin
** Mixture of ZX BASIC and ASM functions and picture references but uses the 168384 address to load into.

This I am hoping would result in files being created that I can then join them together into one TAP file which can then be loaded via an emulator.
The idea is then to be able switch to the relevant bank # to call the relevant function,.

Issue:
When the main,bas is compiled the compiler insists on functions being accessible at runtime, a very logical thing, so the compile fails as the methods are not in main.bas but in the other *.BIN files.

Is there a way around this?
I was using blank labels which helps a bit but I can't really do this with the functions (I have not tried though)

thanks
:-)