String Truncation

Hi guys, I'm just trying to debug this function that truncates a function before an occurance of a character(inclusive of the character). For example, in the string "Testing one two three", truncate the string before the first occurance of the character ' '. The result would be "one two three". Anyway, I'm only an beginner/intermediate skilled programmer and thus I have come here for your help :). The problem i'm getting is related to malloc, it crashes at runtime with a "Unhandled exception at 0x77f75a58". The code is as follows:

EXPORT LPSTR PreTruncateChr(LPSTR lpszString, CHAR cScissors, WORD wNumber)
{
   LPSTR lpszInput; 
   LPSTR lpszFinal = (LPSTR)malloc(sizeof(lpszString));
   LPSTR lpszOutput;
   WORD wCutSize = 0;

   if (lpszFinal == NULL)
      return NULL;

   if (!wNumber)
      return NULL;

   for (WORD wLoop = 0; wLoop < wNumber; wLoop++)
      lpszInput = strchr(lpszString, cScissors) + 1;

   wCutSize = (WORD)(lpszString + strlen(lpszString) - lpszInput);

   lpszOutput = (LPSTR)lpszFinal;

   for (WORD wLoop = 0; wLoop < wCutSize; wLoop++, lpszInput++, lpszOutput++)
      *lpszOutput = *lpszInput;

   *lpszOutput = '\0';

   return lpszFinal;
}

All help is greatly appreciated.