The Sulphurites have lost all three of their previous visits to Gander Green Lane, the most recent of which saw them edged out 1-0 in a League Two fixture that they dominated shortly before Christmas.
On this occasion, there are no points at stake down in South London, however the victors will find themselves just one more win away from a Wembley final.
"We’ve been there three times and lost by the finest of margins on each occasions,” Weaver said.
“It’s been frustrating on the journey home from those games which were all winnable.
“So we have to make sure that we build from the solid platform of Saturday [a 3-0 win over Oldham] which saw all 11 players get behind the ball at times, defend as a team, but attack as a team too and be ruthless when the chances arise.”
Addressing the possibility of what would be a third Wembley appearance in as many seasons, the Harrogate chief added: “It would be unbelievable to get to Wembley again.
“It would be massive for our supporters above anything monetary that would be derived from a win. It’s two games away but you can feel it, it’s tangible, it’s something we’ll be so hungry for.
“It’s a massive game, another big occasion.”
Weaver himself will miss Tuesday's trip to the capital as he continues to self-isolate after testing positive for Covid-19.
Seven-goal midfielder Alex Pattison is however expected to return from injury after missing Saturday's triumph over Oldham, though striker Aaron Martin will not be involved after it was announced last night that he has joined National League title-chasers FC Halifax Town on loan until the end of the season.
Kick-off at Gander Green Lane is at 7.45pm.