Calling LrTasks.execute from within a plug in manager control

Question

I'm working on a Lightroom post-processing-filter plug in which has most of the functionality inside an executable that resides inside the plug in folder.
The executable is responsible for doing the actual photo processing but is also responsible for obtaining and verifying that there is a valid license. This means that I need to let the user eneter an activation code, pass that to the executable which will talk to our server and get a license.
I would like to handle that activation part from the plug-in manager dialog so I've added a top section (see following code) with a text field and a button and I've added code to call the executable when the button is pressed, but the executalbe is never called.
Is what I'm trying to do impossible? Any workarounds?
Thanks in advance!
Eyal
function PluginManager.sectionsForTopOfDialog( f, p )
          p.my_result = 0
return {
          -- section for the top of the dialog
                    bind_to_object = p,
                    title = "MyPlug",
                    f:row {
                              spacing = f:control_spacing(),
                              f:static_text {
                                        title = LrView.bind( "my_result")
                              f:push_button {
                                        width = 150,
                                        title = 'Run Exe',
                                        enabled = true,
                                        action = function()
                                                  command = '"' .. LrPathUtils.child(LrPathUtils.child( _PLUGIN.path, "mac" ), "MyTool" ) .. '" ' .. '-action check"'
                                                  quotedCommand = command  
                                                  p.my_result = LrTasks.execute( quotedCommand )
                                        end,
end

Answer 1

Thanks Rob,
I'm afraid it didn't work for me. The code inside postAsyncTaskWithContext is not executed, as far as I could see. I didn't see any diagnostic messages.
local LrView = import "LrView"
local LrHttp = import "LrHttp"
local bind = import "LrBinding"
local app = import 'LrApplication'
local LrPathUtils = import 'LrPathUtils'
local LrTasks = import "LrTasks"
local LrDialogs = import 'LrDialogs'
local LrRecursionGuard = import 'LrRecursionGuard'
PluginManager = {}
function PluginManager.sectionsForTopOfDialog( f, p )
          p.my_result = 0
          local buttonGuard
return {
          -- section for the top of the dialog
                    bind_to_object = p,
                    title = "MyPlug",
                    f:row {
                              spacing = f:control_spacing(),
                              f:static_text {
                                        title = LrView.bind( "my_result")
                              f:push_button {
                                        width = 150,
                                        title = 'Do Something',
                                        enabled = true,
                                        action = function(button)
                                                  LrFunctionContext.postAsyncTaskWithContext(button.title,function (context)
                                                            p.my_result = 3
                                                  end)
                                        end,
end