>>>STREXTRACT() would require special case handling for the first pair, wouldn't it? It has no way to select a partial string unless it begins with a delimiter - or am I missing something?
>
>

>yourstring="123,456,abc"
>STREXTRACT( yourstring, "", ",")
>

>will extract "123", the first field

So, the delimiter is an emtpy string. This is special case handling, wouldn't you agree?

>

>yourstring="123,456,abc"
>STREXTRACT( yourstring, ",", "")
>

>will extract "abc", the last field, in the above example

[typo?] As a matter of fact, it won't (it will return 456,abc). But if, as was said in the update, a delimiter is inserted at the start of the string, STREXTRACT() can be generalized: STREXTRACT(","+yourstring,",",",",pairnumber,2).