ThingSpeak

Hello!

I`ve got problems with reading last input of a channel field using AT commands, here follows the sketch I'm currently using:

/* String tx_data_r = "GET https://api.thingspeak.com/channels/CHANNEL/fields/4/last.txt?api_key=API_READ_KEY&results=1"; */

String tx_data_r = "GET https://api.thingspeak.com/channels/";
tx_data_r += "CHANNEL";                                                                         
tx_data_r += "/";
tx_data_r += "fields";                                                                    
tx_data_r += "/4/";                                                                            
tx_data_r += "last.txt?api_key=";
tx_data_r += "API_READ_KEY";                                                                 
tx_data_r += "&results=1";                                                                   
tx_data_r += "\r\n";

Serial.print("AT+CIPSEND=");                                                                                                                                              
delay(1000);

Serial.println(tx_data_r.length());                                                                                                                                    
delay(1000);

Serial.println(tx_data_r);
delay(1000);

 This piece of code doesn`t return a valid response, however if I copy/paste
 https://api.thingspeak.com/channels/CHANNEL/fields/4/last.txt?api_key=API_READ_KEY&results=1"
 using a browser I get the right data.

 One more thing, if instead of using a microcontroller I use an USB serial PC interface program  directly connected to 
 my RF module, with                                                                      
 GET https://api.thingspeak.com/channels/CHANNEL/fields/4/last.txt?api_key=API_READ_KEY&results=1
 along with other commands I get the right data too!

 Can anybody tell me what's going on?

 There are no problems with any read related commands.

 If a working sketch is available it will be most welcome!

 Tks in advance for any help!