Problem with char in twitter program

I'm using a library to post on twitter. It's basically this:

 sensorValue = analogRead(sensorPin);  // Reads a LDR @ A0 
if (sensorValue < 100)
{  
  Serial.println("Nobody on the living room... forever alone!!!");
  char msg[] = "Nobody on the living room... forever alone!!!";
  twitter.post(msg);
...

No problems up to this point.
But twitter usually doesn't accept repeated messages from external apps.
So my problem is that I'm trying to use a counter or something just to make some difference between texts.
Then I tried these codes:
1st one:

...
  counter++; //declared as int in the beggining of the program
  char msg[] = "Nobody on the living room... forever alone!!! Counter: "+counter;
  Serial.println("Nobody on the living room... forever alone!!! Counter: "+counter);

Didn't work!!
2nd one:

...
  counter++; //declared as int in the beggining of the program
  const String s("Nobody on the living room... forever alone!!! Counter: "+counter); 
  char charArray[45];
  ((String)s).toCharArray(charArray, 45);
  char msg[] = charArray;
  Serial.println("Nobody on the living room... forever alone!!!"+counter);

The message i receive when i try to compile is: initializer fails to determine size of 'msg'

Do you guys have any suggestion?!
This is such an idiot thing, but i'm really stuck here!!!

So you want advice on how to spam Twitter do you?

Come on!! Spam?!
Sorry my friend, I just want a routine that allows me to know when my garage door and other locks are openend during the day..
If u don't know what to say, if u don't know how to help, don't be unpleasant and shut up!

This exact question comes up every couple of weeks. Did you search the forum for twitter?