You can open/import INDD files to QuarkXpress with the help of specialized plugins from Markzware and then save them to QXP format, which is what indd to qxp conversion represents. Not perfect, but atm the only option how to convert INDD to QXP.
Open INDD file Open QXP fileQuarkXpress Xtension that adds support for Adobe InDesign formats
QuarkXpress for Mac Xtension that adds support for Adobe InDesign formats