Outputting result matrix using SamUL to excel

After making a matrix of data, I want to save it into a csv excel file. But when I do, the indices are ignored. For example:

data[0,0]
data[0,1]=-2
data[1,0]=5
data[1,1]=1
WriteTextFile("/Users/cp....csv",data)

Returns 3 -2 5 1 in my excel sheet (each number in a different column in row 1).

Is there not a way to write data matrices to excel? (Using a Mac)

Hello, WriteTextFile() writes a string to the file.
Here's SamUL script that should work (Note that in SAM 2014.11.24, LK replaces SamUL):
data[0,0]

data[0,1]=-2

data[1,0]=5

data[1,1]=1
n_rows = length(data)

n_cols = length(data[0])
str_data = ""

str_row = ""
for (i=0;i