Activities/tracks.

Apologies if this is a basic question...

I'm in the process of 'upgrading' from Gpsmap 64 to 66i. I use if for my work, surveying in forests. A requirement is that I save the track with a specific name - a UK Grid Reference. With the 64, I simply renamed the gpx file before saving it, and then when I connected the unit to my PC, they all appeared as I'd named them. With the 66, it seems they are saved as an activity, and I then have to specifically save them as tracks. Even if I have renamed them at the activity stage, they still appear with the time format when viewed as tracks. If I am saving several tracks a day, it is very tedious. 

What I need is to be able to rename a track as soon as I've finished it , and for that to be the name I see when I connect to my PC to download the gpx files.

Am I missing something fundamental?

Thank you.

Norman