Believe me when I say you're going to be chasing your tale for a while if you're always going to desire that Velvia look on your digital files. There are many color presets out there for Lightroom, Photoshop, etc, but digital is going to always offer a baseline and it'll be up to you in how you want to alter it. I shoot about 60/40 film to digital and love the way Portra 160VC looks. I've tried for ages to match that look with my 5D. Sometimes I get it to match, other times, I don't. I could probably hire a professional retoucher/color expert to do it for me, but I'd rather just shoot the film if that's the look I need.
Keep in mind also that you're comparing slides which I'm assuming you're viewing through a loupe & lightbox(?) versus digital images on a screen that may or may not be calibrated. Digital images give incredible flexibility in terms of color tweaking, which can be overwhelming if you're always trying to match a film's color that may shift depending on other physical variables (temperature, age, chemicals, etc).