Custom Roof Connection

Hello,
I have a unique connection condition I'm trying to resolve, and I think Hilti may have the right products to help us do so. Attached is a pdf of a few drawings and the contractor's proposed assembly for you to reference. Our project is an existing structure at the University of Wisconsin - Madison. We were not involved with the engineering on the front end but have been hired by the architect to consult on detailing efforts.
The primary structure is steel framed with a stone exterior facade against the roof and walls. Our challenge exists at the sloped roof where we are trying to anchor a steel angle to support the stone on the roof. The steel structure is roughly 3" offset back from the roof deck due to insulation and we are trying to bridge that gap, support the stones, and resist any tension reaction produced. Our contractor has presented a custom assembly concept and I think it is a viable option with the addition of the proper Hilti fastener. I'm looking for an expansion fastener that could be installed from above, through the steel bent plate/steel beam top flange, without requiring an underside bolt to complete the clamping action. Again, attached is a combined pdf of project drawings, the contractors proposed assembly, and original RFI. I would love to speak with a Hilti specialist sometime Monday 4/22. I have included my contact information below and look forward to speaking soon.

Kara Bruder, PE
Oneida Total Integrated Enterprises (OTIE)

Seattle, Washington
C: 859.992.8611
KBruder@oescgroup.com