The best way to do this would be to populate a tracking code or variable of some sort when the referrer is your blog. You might consider creating a processing rule to do this (if you don't want to wait for a development cycle to release a code change).
Otherwise you could try something like the following (which will ONLY work if your blog has a unique ref-domain, that is NOT part of your internal URL filters):
![1526194_pastedImage_1.png 1526194_pastedImage_1.png](/t5/image/serverpage/image-id/12371i5BFBC05FCD8DBA23/image-size/large?v=v2&px=999)