HOW TO CREATE/DUPLICATE A NEW CHARACTER TO GO TO TRISTRAM

Hello everyone
Well, sorry in advance if I ask a question that has already been answered... I searched and I didn't find it

Before explaining the problem, I'll give you the situation
1) I'm playing DIABLO 2 RESURECTED on PC - in solo mode and not online
2) I just finished the game in "normal" with my paladin
3) Thinking I could get

Wirt's Leg back in

Tristram, I started the game again in NIGHTMARE mode... with the SAME character
4) from what I understand... it's a mistake: because apparently you have to start a NEW game with a new character...

But mine is so well equipped with good stats... that frankly if I start from the beginning with a new one... I'm going to struggle

Here's my question
- I'd like to start a new game to go back to

Tristram
-... but is it possible to:
>>> create a new perso
>>> with a new name
>>> and give him all the characteristics of my old one...

So, I will have started a NEW game, with a NEW character but with the abilities of the old one
It will be easier for me to get to

Tristram

I imagine that it will be necessary to duplicate the SAVEGAME files but before doing anything, I wanted the expert's opinion

Thank you!

I'm not quite understanding the problem.

1)Using your current character, start a new game and select normal difficulty. Go to

Tristram and pick up the leg.
2)Go to the

Rogue Encampment and fuse the leg with a tomb of town portal in your

Horadric Cube.
3)A portal appears to the secret level.
You can repeat steps 1-3 as many times as you like. After you finish the

Baal quest on nightmare difficulty then you can do it on nightmare difficulty too.

Your character can change difficulties every time you play, that's not a problem.