Quick Script - allows you to create custom button groups for "extending" modifiers or executing custom MaxScript code. It also has a separate section for quickly launching external scripts (*.ms, *.mse)
Brief instructions for use:

Main Window (Quick Script)

< / :: / > buttons at the top: control window docking (left, floating, right).
Preferences button: Opens the Settings Manager to manage your custom button groups.

Creating buttons (Button Editor)

Click "Add (+)" in the desired group (Rollout) or Scripts section.
The "Button Editor" window will open.
Select "Command Type":
Modifier (From List): Select one or more modifiers from the list using the Search Filter. The "Refresh Modifiers List" button refreshes the modifier list by scanning 3ds Max.
Custom Script (Code): Enter the button name and the MaxScript code itself
Click "SAVE BUTTON(S)"

Launch, edit and delete

Run a button/script: Just click on it.
Editing a button/macro: Click on the button while holding Ctrl.
Deleting a button/script: Click on the button while holding down the Delete key.