Mills, 26, told BBC Sussex and BBC Surrey: "We're going to go up there to win a game. We'll treat it as if we are playing a Conference team.
"We'll prepare the same way and try and play. Nothing is impossible."
The Blue Square Bet Premier outfit have not lost in the league since October and are currently on an 11 match unbeaten run.
The former Rotherham defender added: "We're under no illusions over the mountain of a the task we are up against but we believe in what we are doing.
"We're not going up there to make up the numbers or be over-awed at the stars they've got.
"We genuinely think we can win."
Source: BBC Sport
Source: BBC Sport