I have the AMC series of Apex, if you have the HPGL one it may be different, but I doubt it. Create your design on Corel, export it as a .plt file, remember not to have any fills checked in the export box. It helps if you make the drawing bigger. So if you have a page setup in corel as A4 or Letter size, hit f3 to zoom out, select everything and make it ten times bigger, then export it
Start JLS software, create a job, then import the plt file into an appropriate epl directory.
I did read a message here some time back that someone creates the file in corel then does a copy and paste. Well this does work, but the graphic appears within JLS upside down and as a mirror version, which takes a bit of sorting.
If you have a problem, get back to me

Simon Cork
Sheffield UK