Open Paint shop Pro, go to file, scroll down and click on batch processing,  it will ask you to browse for the files you wish to convert and which format you wish to save them in.  That is all.  As far as I know there is no limit to the number of files you can convert.  You can also to a batch rename the same way. 

Hope this answers you question

Oh here is a link to corel's instructions if you have a problem.  You do not need to sign in.  I don't think anyways. 

http://product.corel.com/help/photopro/540243425/EN/Doc/wwhelp/wwhimpl/js/html/wwhelp.htm?context=Corel_PaintShop_Photo_Pro_Help&topic=0x00000&single=

Copy the whole link into your web browser