Why not just create a hash table and have each item use tokens like this:
joe smith38jane smithspoons
Then you can use $gettok($hget([color:purple]myhashtable, item-number).data, token-number, 1)[/color] to refer to peices of data. Using hash table indexes like that isn't vey efficient, but it's probably still fast enough.
The maximum length for any string in mIRC is approx. 940 characters, minus command names you get a practical length for variables or parameters of around 920 characters.