Retrieves one or more characters from the specified position in a string.
NewStr := SubStr(String, StartingPos , Length)
The string whose content is copied. This may contain binary zero.
Specify 1 to start at the first character, 2 to start at the second, and so on (if StartingPos is 0 or beyond String's length, an empty string is returned).
Specify a negative StartingPos to start at that position from the right. For example, -1 extracts the last character and -2 extracts the two last characters (but if StartingPos tries to go beyond the left end of the string, the extraction starts at the first character).
If this parameter is omitted, it defaults to "all characters". Otherwise, specify the maximum number of characters to retrieve (fewer than the maximum are retrieved whenever the remaining part of the string is too short). You can also specify a negative Length to omit that many characters from the end of the returned string (an empty string is returned if all or too many characters are omitted).
This function returns the requested substring of the specified string.
MsgBox SubStr("123abc789", 4, 3) ; Returns abc