This is a simple way:
#include <array.au3>
#include <file.au3>
Dim $oneDarray
_FileReadToArray(@ScriptDir & "" & "CSVfile.txt", $oneDarray)
$columnsCounter = stringsplit($oneDarray[1],",")
Dim $twoDarray[$oneDarray[0] + 1][$columnsCounter[0] + 1]
For $x = 1 to ($oneDarray[0])
$oneRow = stringsplit($oneDarray[$x],",")
For $y = 1 to ($columnsCounter[0])
$twoDarray[$x][$y] = $oneRow[$y]
Next
Next