The winger-turned-defender, who had a two-year spell in charge of the Hornets between 2013 and 2015, has appeared 616 times for Horsham, surpassing Mark Stepney's long-standing record.
He was an integral part of the fabled Hornets team that reached the second round of the FA Cup in 2007-08.
Including games for the likes of Lewes, Burgess Hill Town and Eastbourne Borough, the Sussex legend has made more than 800 appearances since his senior debut in 1998.
Charman said: “I’m extremely proud of what I’ve achieved. I’ve enjoyed every single moment and Saturday is a chance for me to say thank you very much as well.
"I’ve been hugely supported by the teams I’ve played with, especially at Horsham and Bognor.
“I’ve always connected well with supporters. They’ve connected well with me because they know every time I’m on the pitch I’ll give them everything I’ve got and I’ll come off saying ‘I couldn’t have achieved any more’.
“I do think it’s important after games to meet these people that come down and support you every week and get to know them.
“I’m hopeful that as many people as possible get down to Horsham on Saturday so I can get to say thank you to them as well.”
A host of Horsham favourites past and present, including 2007-08 FA Cup heroes Eddie French, Rob Frankland, Lee Carney, Carl Rook, Jamie Taylor, John Westcott and Nigel Brake, will don Horsham’s yellow and green once more in the match.
The Hornets hero said he was thoroughly looking forward to ‘seeing the people that I love the most all in one stadium at the same time’.
“I’m absolutely buzzing for it,” he said. "The things I’m looking forward to most are seeing players I’ve played with recently and in the past.
“I’ve got about ten or 12 players coming down that I played with back in the early 2000s and the 2010s. That’s what I’m looking forward to most, seeing the people that I love the most all in one stadium at the same time.”
Tickets for Saturday’s match are £11 for adults, £6 seniors, students and under-16s, £2 for under-16s.