Code:
@Convert to thumb
add r2,pc,#1           
bx r2
.thumb

ldr r0, TextPointer
ldr r0,[r0]
ldrh r1,=0x3C16
ldrh r3,[r0,r1]
ldrh r2,Activator
cmp r3,r2
bne Exit
strh r1,[r0,r1]

ldr r0,Map
ldrh r1,=0x1FFE
ldrh r2,=0xFFF1
ldrh r3,=0x144E

Search:
ldrh r4,[r0,r1]
cmp r4,r2
bne NotReplace
strh r3,[r0,r1]
NotReplace:
sub r1,#2
bpl Search

Exit:
bx lr

.arm
TextPointer:
.long 0x21CAF6C
Map:
.long 0x21E3124
Activator:
.ascii "re"
Code:
023FF090 012FFF11
E0000000 0000004C
E28F2001 E12FFF12
6800480B 5A43490B
42934A08 5241D10A
49094805 4B0A4A09
42945A44 5243D100
D5F93902 00004770
021E3124 00006572
021CAF6C 00003C16
00001FFE 0000FFF1
0000144E 00000000
023FF090 E3520003
try that

Just type "re" and it should work