How to assign a hotkey using alt search and replace?

I’m using LO 4.3.2 under Mint 17 Mate on a PC. I downloaded and installed the alt search and replace utility, which is a great improvement over the search and replace built into Write. I want to assign the alt version to ctrl-H, now used by the built-in version. But using Tools, Customize, Keyboard doesn’t list the alt search and replace under Edit or anywhere else I could find. I tried writing a macro that I could name and assign, but I can’t do that without knowing a name for the utility that the macro utility can recognize. Any suggestions?