Can anyone advise me whether it's possible to replace the usual low E string when using open C tuning so that it won't be so slack?

I'm new to this game - my first attempt at playing this way (Gloomy Winter - Dougie Maclean).

Also - how do you do a search on this forum? I've tried many times on lots of topics but never had a hit (e.g. surely ther are psoting on 'open tuning')

Also should I get an email if someone replies to this? Is there a way of setting it up to do that?