MIPS 1D Integer Array, inserting at index - arrays

Question

I'm new to MIPS and having some trouble with my program.
Right now my code works at inserting an integer value into the array at a specified index. But currently, when the integer is inserted it replaces the value that was previously there. How do I instead shift all elements after said index so the array's length increases by 1 and no values are lost?
Note that I'm using a special integer -22 to indicate the end of my array.
Any help would be greatly appreciated! Thank you!
Below is my code:
.data
beginarray: .word 1, 2, 3, 4, -22
array: .space 4000
str_command: .asciiz
str1: .asciiz "\nEnter an Integer: "
str2: .asciiz "\nAt what index: "
.text
.globl main
main:
# get length
la $a0, beginarray
jal length
addi $s0, $v0, 0 # $s0 = returned length
# copy beginarray into array
la $a0, beginarray
la $a1, array
jal copyarray
jal insert
# print array
la $a0, array
jal printarray
li $v0,10
syscall
# takes pointer to array as input
length: addi $t0, $zero, -22 # $t0 = -22
addi $v0, $zero, 0 # $v0 = 0 (length)
add $t1, $a0, $zero # $t1 = pointer to first int
calclength: lw $t2, 0($t1) # $t1 = value of current int
beq $t2, $t0, returnlength # if $t1 = -22
addi $v0, $v0, 1 # increment length
addi $t1, $t1, 4 # move pointer to next int
j calclength # loop
returnlength: jr $ra
# takes two pointers as input (pointer to first array and pointer to second array)
# copies contents of first array into second array
copyarray: addi $t0, $a0, 0 # $t0 = pointer to array1
# addi $t1, $a1, 0 # $t1 = pointer to array2
addi $t4, $zero, -22 # $t4 = -22
calccopy: lw $t2, 0($t0) # $t2 = value of array1
#lw $t3, 0($t1) # $t3 = value of array2
sw $t2, 0($a1) # store int in array
beq $t2, $t4, returncopy # if $t2 = -22
addi $t0, $t0, 4 # move a1 pointer to next int
addi $a1, $a1, 4 # move a2 pointer to next int
j calccopy
returncopy: jr $ra
# print array
printarray: add $t1, $a0, $zero # $t1 = pointer to first int
addi $t0, $zero, 0 # set counter to zero
printloop: beq $t0, $s0, done
# load word from addrs and goes to the next addrs
lw $t2, 0($t1)
addi $t1, $t1, 4
# syscall to print value
li $v0, 1
move $a0, $t2
syscall
# syscall for printing space
li $a0, 32
li $v0, 11
syscall
#increment counter
addi $t0, $t0, 1
j printloop
done: jr $ra
insert:
li $v0, 4 # system call code for print_str
la $a0, str1
syscall
li $v0 5 # system call code for read_int
syscall
move $t3, $v0 # $t3 = integer entered
li $v0, 4 # system call code for print_str
la $a0, str2
syscall
li $v0 5 # system call code for read_int
syscall
move $t1, $v0 # $t1 = index entered
li $t0, 0 # $t0 = counter
la $t2, array # $t2 = base address of array
for: bge $t0, $t1, end_for
add $t2, $t2, 4 # get address of next array element
add $t0, $t0, 1 # increment loop induction variable
b for
end_for:sw $t3, ($t2)
jr $ra