Thanks for helping me, I managed to get this result in the end:
.align 2
.thumb
main:
push {r0-r1,lr}
ldr r0, .pointer
ldr r0, [r0]
ldr r1, .var
ldrh r1, [r1]
add r0, r0, r1
ldr r1, .varend
ldr r0, [r0]
strb r0, [r1]
pop {r0-r1,pc}
.align 2
.pointer:
.word 0x020370C0
.varend...