Matiri Valley to Fyfe River?

Hi I've been eyeing up a route from the Matiri River Track to the Fyfe River track - has anyone been this way before? There's an unnamed lake north of McConchies Hut with peaks to the east that could give access the upper Sandstone Creek, and from there into the Fyfe. I can't find any record of anyone going this way before so would love to hear from anyone familiar with the area.