INSERT

 ──INSERT(new,target─┬─────────────────────────────┬─)─────
                       └─,─┬───┬─┬──────────────────┬┘
                           └─n─┘ └─,─┬──────┬─┬────┬┘

                                     └length┘ └,pad┘

INSERT inserts the string new, padded to length length, into the string target after the n th character. If specified, n must be a nonnegative whole number. If n is greater than the length of the target string, padding is added there also. The default pad character is a blank. The default value for n is 0, which means insert before the beginning of the string.

Here are some examples:

INSERT(' ','abcdef',3)         ->    'abc def'
INSERT('123','abc',5,6)        ->    'abc  123   '
INSERT('123','abc',5,6,'+')    ->    'abc++123+++'
INSERT('123','abc')            ->    '123abc'
INSERT('123','abc',,5,'-')     ->    '123--abc'