Here's an ahk script that anyone can use and kind of works, need to mess with delays. Rebind ScrollLock to whichever key you want to use the macro for. Rebind 4 for wherever you put your grenade and x for whichever key is your pickaxe.
~ScrollLock::
while KeyIsDown := GetKeyState("ScrollLock")
{
Send, {4}
Sleep, 40
Send, {X}
Send, {LButton Down}
Sleep, 350
Send, {LButton Up}
}
return
ScrollLock up::
return