Our Logitech contact explained that it's not possible.
"You want to know if the G11 Gaming Keyboard can loop macros--- in other words, so the game doesn't log off the player due to inactivity?
The answer would be no.
The G11 keyboard software only allows the recording of macros, but does not loop it. (The looping feature makes troubleshooting difficult.)
Most players who have this macro-looping feature use a separate third party software or program to send out that keystroke and create the looping of macros.
Also, it depends on what game you're playing, many people write game add-ons for particular games to simulate functions like looping macros. For example in "Ultima Online" someone wrote UOLoop- a program that lets you loop UOA macros for that game."
So, the only way is to use other applications, like the ACTool I mentioned or something similar. The G11/15 is great for simple macros, but anything more advanced is a little trickier.