If it's a Z80 Compatable system, I'm just wondering if it's got something like LDIR or LDDR?
That's what I'd do on my system, so you can load the file somewhere else from Disk and use something like this:
LD HL,&<address of the code>
LD DE,&<where it needs to go>
LD BC,&<the length of it>
LDIR
RET