addon for you function.
How to create a random test text (Delphi script)

function RandomText(ALen: integer): OleVariant;
var StrTable: string;
N, K, X, Y: integer;
tmpstr: string;
LengthStrtable:OleVarinat;
begin
tmpstr:= ''; StrTable:='013456789АаБбВвГгДдЕеЁёЖжЗзИиЙйКкЛлМмНнОоПпРрСсТтУуФфХхЦцЧчШшЩщЪъЫыЬьЭэЮюЯяAaBbCcDdEeFfGgHhIiJjKkLlMmNnOoPpQqRrSsTtUuVvWwXxYyZz';
LengthStrtable := Length(StrTable);
if (ALen >LengthStrtable) then
K := LengthStrtable-1
else
K := ALen;
SetLength(tmpstr, ALen);
N := 0;
while N < K do
begin
X := Random(LengthStrtable) + 1;
if (pos(StrTable[X], result) = 0) then
begin
inc(N);
tmpstr[N] := StrTable[X];
end;
end;
Result:= tmpstr;
end;