Holdsworth, who played six games on loan for City in 2002, has masterminded The Exiles promotion, their first in 15 years, into the top flight of the Conference with a side that had former Sky Blue Craig Reid getting a good number of goals.
"We have had such great times this year and I'm now looking forward to sustaining our conference premier status and seeing just how far we can take this group of players whilst building the club," said Holdsworth to his club's website.
"It's going to be a great challenge competing against some big names in this division and we are all looking forward to our pre-season programme.
"The importance of full-time training cannot be underestimated and will be a brilliant chance for us to work with players."