!!!SUBSTR 
!Functionality:
This Oracle function allows you to extract a substring from a string (text field)

!Parameters:    
|STRING    | The source, or original, string
|START     | The character that you are starting the extraction from.  The first character is always 1
|LENGTH    | (optional)  The number of characters to extract.  If this parameter is omitted, the extraction will go to the last character of the string

!Returns: 
Text

!Errors:  
None

!Operations: 
If start position is 0, then start position is taken as 1

If start position is negative, then substr starts at the end and counts backwards

If length is negative, then NULL is returned
 
Example:

 {{Substr(~,3,4)}}

will return, from a value of ABCDEFGHJK the value DEFG  (third character for four characters)