There is a military q & a found by googling: "Milgenire"
All British Army records are found at the National Archives Kew but they have given permission for a paywebsite to have records on line. They may also be available at the PRONI in Belfast. I'm assuming you have googled the 87th. Foot already.
There are birth records on line for Fermanagh but not till civil registration of 1864 and marriages 1846 but earlier records exist but unreadable. There is a variety of
information on these websites:www.censusfinder.com
+ Fermanagh (these maybe of assistance for the early records for Fermanagh.