I made this ini file:
[JHamill]
key1=value1
key2=value2
key3=value3
I took a bit of code from IniReadSection example and modified this to be able to use it for a drop down menu.
$var = IniReadSection("test.ini", "JHamill")
$str = ""
For $i = 1 To $var[0][0]
$str &= $var[$i][1] & "|"
Next
$str = StringTrimRight($str, 1)
GUICreate("JHamill GUI combo")
GUICtrlCreateCombo("", 10, 10)
GUICtrlSetData(-1, $str)
GUISetState()
While 1
$msg = GUIGetMsg()
If $msg = -3 Then ExitLoop
WEnd
Here you see you don't have to make a new array to make it work. But since you asked, here is the same thing by making a new array first, copying only the value elements, and then using that array to fill the combo box:
#include <Array.au3>
$var = IniReadSection("test.ini", "JHamill")
Local $arr[$var[0][0]]
For $i = 1 To $var[0][0]
$arr[$i-1] = $var[$i][1]
Next
_ArrayDisplay($arr)