G codes extract one or more contiguous strings (separated by a specified character), from a field value.
m is the number of strings to skip. If omitted or zero, extraction begins with the first character.
x is the separation character.
n is the number of strings to be extracted.
The field value can consist of any number of strings, each separated by the specified character. The separator can be any non-numeric character, except a system delimiter.
If m is zero or null and the separator x is not found, the whole field will be returned. If m is not zero or null and the separator x is not found, null will be returned.
Input conversion does not invert. It simply applies the group extraction to the input data.
If the field contains "123.45", 123 will be returned. You could also use "G.1" to achieve the same effect.
If the field contains "ABC/DEF/GHI", GHI will be returned.
If the field contains "ABC,DEF,GHI,JKL", ABC,DEF,GHI will be returned. Note that the field separators are included in the returned string.