I didn't try this, yet, but reading the code, something like that could work:
&loadModels = `yourPackageName`
&leftJoin = `[{"class":"yourClass","alias":"theAlias","on":"modResource.id = theAlias.resource_id"}]`
&select = `["theAlias.name AS theAlias_name","theAlias.description AS theAlias_description"]`
you need to try this by yourself and see what happens.
with migxLoopCollection the same would look like that:
&packageName=`yourPackageName`
&classname=`modResource`
&joins=`[{"class":"yourClass","alias":"theAlias","on":"modResource.id = theAlias.resource_id","selectFields":"name,description"}]`