Hero Lab for Old-School Essentials (or a good substitute)
 

Greetings everyone.

Is there a way to use HLC to create and manage OSE characters? If not, is there a good app to do that?

Thank you in advance for your help and time.

Hero Lab doesn't have a package for D&D, AD&D or retro-clones like OSE. There has been some discussion about people making/wanting one but nothing has happened to this point. (You can't simply modify something existing, you would need to create it from scratch.)
Do a google search on OSE character generator - you'll get lots of options.