練習

on toDig(tarNum, tarDig)
	
	if not (tarDig > 0) then
		set tarDig to 2
	end if
	
	set addZero to "" as string
	set retNum to "" as string
	
	if tarNum < 10 ^ (tarDig - 1) then
		repeat (tarDig - (length of (tarNum as string))) times
			set addZero to addZero & "0"
		end repeat
		set retNum to addZero & tarNum
	else if tarNum >= 10 ^ (tarDig - 1) then
		set retNum to items 1 thru tarDig of (tarNum as string)
	end if
	return retNum
end toDig

桁数を整形するだけ。深い意味は無いです。

on randomStr(wordLen)
	set seedStr to ""
	set seedChar to "123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
	
	repeat wordLen times
		set seedStr to seedStr & item (random number 61) of seedChar
	end repeat
	return seedStr
end randomStr

数字と英字を含めたランダムな文字列を作る。ドッカに同じサンプルがあったと思うけど忘れた・・・問題あればスグ削除します。