Yes, you should be able to do this. You'd partition the drive with a GPT partition table (of course), then use Boot Camp to add a Windows partition and Disk Utility to split the data partition off on the fly. There are some restrictions to the volumes that Boot Camp can add a Windows partition to, so you might need to do the partitioning in a particular order. And I'm pretty sure you can't just make three partitions and then use Boot Camp to install Windows on one--at least on earlier versions of Boot Camp, it needs to partition the drive itself or Windows won't install (ran into this during installation of a bunch of new computers at work).
As for formats, the Data drive can be in Fat32, if you don't have files larger than 4GB you want to put on it, and it should then be acessible from both Windows and the MacOS. You could, alternately, install an NTFS write driver on the MacOS and partition it in NTFS, though my personal luck with those drivers hasn't been great. Or you could install an HFS driver on Windows and make it Mac-native HFS--that's probably what I'd do.
ExFAT is another possible option; it allows large files, and both the macOS and Win7 are supposed to be able to read and write to it, although the one time I tried a GPT/ExFAT flash drive, Win7 didn't recognize it. If you try it and it doesn't work, it's of course easy enough to just reformat the partition.