It can be done. Do you have the paid membership to groundspeak? If so, there is an option for “caches along a route,” and it tells you how to go about doing this.

I haven’t used it that much. I look on the maps for some caches along the way and create a bookmark list of the ones I want to do. Then you can create the PQ from that bookmark. Hope this helps.

You might also consider using GSAK for your route management. It’s filter tool is far superior to the options in the pocket Query. What I usually do is setup several PQs that cover the whole route, import them into GSAK, then pick and choose in GSAk which ones I want. Of course, that’s not always necesasary, most times the PQ options are enough to satisfy the selection needs. But you might want to consider it.

It helps me especially in the aera of creating the series of files for the GPS since mine only accepts 200 waypoints per file. On a longer trip, that’s not enough. GSAk makes that easier to manage. I also like to be able to go in and add notes (like correct coordinates on puzzle caches) and mark the specific ones I know I want to hit and the ones I don’t (those can be flagged and ignored) I can also add notes to the GPX export that I use for CacheBerry.

1000 ways to skin a cat. Hopefully something here is helpful for your particular situation.

The other strategy is to just stop at every dead end along the way and check the guard rail.