Exchange data with Excel

Hi all, 
I have been reading the comments on how I can write a script with the SDK tool.
I tried to do a test by putting a file in the C drive calles 'test'
xlobject=xl_create;
xl_open(xlobject,"C:\test.xlsx");
data_str=xl_get(xlobject,"Mydata");
xl_close(xlobject);
xl_free(xlobject);
data=real_array(data_string);

I have the following message error when trying to run the script.
[1] referencing unassigned variable:xl_create
 
Is it possible to know why? are there any templates we can use which explains this better?

kind regards
Sabrina