how to rotate matrix scroll by 90 degrees in code

Sure.

   int c = (font8x8[(number * 7) + 0] & (1<<a))?0x80:0;      // Index into character table to get row data
   c |= (font8x8[(number * 7) + 1] & (1<<a))?0x40:0;
   c |= (font8x8[(number * 7) + 2] & (1<<a))?0x20:0;
   c |= (font8x8[(number * 7) + 3] & (1<<a))?0x10:0;
   c |= (font8x8[(number * 7) + 4] & (1<<a))?0x08:0;
   c |= (font8x8[(number * 7) + 5] & (1<<a))?0x04:0;
   c |= (font8x8[(number * 7) + 6] & (1<<a))?0x02:0;
   c |= (font8x8[(number * 7) + 7] & (1<<a))?0x01:0;

This rotates the display 90/270 degrees. Depending on your physical orientation, it may be right-side-left. In that case, switch 0x80 with 0x01; 0x40 with 0x02; ...