How do I make a in game command to link people?

If you mean like :kill me or :tp others me then here is the code

local admins = {"yourname"}
local prefix = "!"

function isAdmin(player)
    for i,v in pairs(Admins) do
    if v == player.Name then
        return true
    end
    end
    return false
end

function GrabPlayers(speaker, input)
    local collectplayers = {}
    if input:match("^!") then
        return FindPlayers(speaker, input:sub(2), true)
    elseif input == "me" then
        table.insert(collectplayers, speaker)
    elseif input == "all" then FindPlayers = function(speaker, input)
        local collectplayers = {}
        if input:match("^!") then
            return FindPlayers(speaker, input:sub(2), true)
        elseif input == "me" then
            table.insert(collectplayers, speaker)
        elseif input == "all" then
            for _,v in pairs(game:GetService("Players"):GetPlayers()) do
                table.insert(collectplayers, v)
            end
        elseif input == "others" then
            for _,v in pairs(game:GetService("Players"):GetPlayers()) do
                if v ~= speaker then
                    table.insert(collectplayers, v)
                end
            end
        else
            for _,v in pairs(game:GetService("Players"):GetPlayers()) do
                if v.Name:lower():sub(1,#input) == input:lower() then
                    table.insert(collectplayers, v)
                end
            end
        end
        return collectplayers
    end
    for _,v in pairs(game:GetService("Players"):GetPlayers()) do
        table.insert(collectplayers, v)
    end
    elseif input == "others" then
        for _,v in pairs(game:GetService("Players"):GetPlayers()) do
            if v ~= speaker then
                table.insert(collectplayers, v)
            end        
        end
    else        
        for _,v in pairs(game:GetService("Players"):GetPlayers()) do
            if v.Name:lower():sub(1,#input) == input:lower() then
                table.insert(collectplayers, v)
            end
        end
    end
    return collectplayers
end

game:GetService("Players").PlayerAdded:connect(function(player)
    if isAdmin(player) then
            player.Chatted:connect(function(message)
        if message:sub(1,6):lower() == Prefix.."kill " then
            local Target = GrabPlayers(player, message:sub(7))
            for index,target in next,Target do
                if target.Character then
                    if target.Character:FindFirstChildOfClass("Humanoid") then
                    target.Character:FindFirstChildOfClass("Humanoid").MaxHealth = -1000
                target.Character:FindFirstChildOfClass("Humanoid").Health = -1000
                end
            end
            end
        end
        end)
    end
end)

Then if you say !kill me or !kill others, it will kill you or all other players besides you.