Booking multiple legs with SQ via VA

[SheikYerbouti]

I'm booking a holiday to Italy with SQ.

I'd like to fly us there and halfway back on a paid ticket, and the final leg of SIN-SYD on points.

SYD-SIN-FCO/MXP paid in Y
FCO/MXP-SIN paid Y
SIN-SYD reward in J redeeming VFF points

Any advice on how I can book this on a single itinterary, rather than multiple 1-way legs?

Ideally through VA for SCs and Sectors.

 

[SCM]

I just asked a similar question elsewhere, also curious.