The location of the various Scratch Disks will not affect the Export destination drive. In the Export dialog, you should have the option to establish the destination drive and folder, plus the name of the Exported output file. Do you not have that option in the Export dialog?
Are you doing a direct Export, or using AME (Adobe Media Encoder)?
I had the same issue years ago when Adobe updated things...in AME, just below where you choose the Format and Preset, look for the yellow text, which by default is usually "Sequence 1.mov" or whatever extension suits the current format. Just click on that name and then you can select destination AND a new name.
Safe Harbor Computers
That has always been less than inuitive.
Seems like it would be easy to fix the "label" so it was more obvious.
AME- found it, thanks guys.