How do i choose a part based on a String Value?

So basically when a player touches a block it removes a point from brick colours team and gives a point to the person who touched its team, I have a StringValue with the Value as the Team Name meaning i can get the players team from that String value but how would i use that Value to select a thing (An int value in this instance).

function onTouched(hit)
	
	local Red = game.Workspace.Game_Files.Round.RedNum
	local Blue = game.Workspace.Game_Files.Round.BlueNum
	local Yellow = game.Workspace.Game_Files.Round.YellowNum
	local Team = hit.Parent.Team.Value

	if script.Parent.Color == 'Tawny' then
		Red.Value = Red.Value - 1
	game.Workspace.Game_Files.Round. (This is where i want the String value to be used)
	end
end

connection = script.Parent.Touched:connect(onTouched)

I've tried this but this also doesn't work, giving this error:

Workspace.Floor_Tiles.Column_1.Floor_Tile.Colouring:7: attempt to index a nil value

function onTouched(hit)
	
	local Red = game.Workspace.Game_Files.Round.RedNum
	local Blue = game.Workspace.Game_Files.Round.BlueNum
	local Yellow = game.Workspace.Game_Files.Round.YellowNum
	local Team = hit.Parent.Team
	local TeamValue = game.Workspace.Game_Files.Round:FindFirstChild(tostring(Team)).Value
	local Colour = hit.Parent.Colour

	if script.Parent.BrickColor == 'Tawny' then
		Red.Value = Red.Value - 1
		TeamValue = TeamValue + 1
		script.Parent.Color =  Colour.Value
		
	end
end

connection = script.Parent.Touched:connect(onTouched)