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)