LXBeams running on OS X can import dmx from either Art-Net or sACN. QLC+ has the ability to send Art-Net output and control LXBeams.
To make this work, in LXBeams preferences, you would select the Network tab and choose the appropriate Art-Net connection based on the Mac's IP address. (If you're not sure choose 10.x.x.x) Then, you would select File->Import->DMX. LXBeams will search for an available network connection starting with either 10. or 2. depending on what you selected. If it does not find an available connection with one of these IP addresses, it will pick a default connection.
In QLC+ you set the first universe of output to Art-Net. If you have a 10. or 2. address available be sure to configure the output to that address. If you do not have a 10. or 2. IP address setup in the Network Preferences, you may need to try different connections to see which one that LXBeams has defaulted to. Then, you should be able to control lights in LXBeams with QLC+. Keep in mind that the connection is by dimmer and in order for lights to respond to DMX input, you will need to assign dimmers to them.