@TSPACE[string]: Returns the number of white space characters (0x09 - 0x0D or 0x20) in string.
See also: @TALNUM, @TALPHA, @TASCII, @TCNTRL, @TDIGIT, @TLOWER, @TPRINT, @TPUNCT, @TUPPER, and @TXDIGIT.
Example:
echo %@tspace[ ]
3
echo %@tspace[hello world]
1