In that case you can consider
Longcross - Sandhurst SDR at £7.80
RPs:
Longcross - Ascot, Staines, Surbiton, Woking
Sandhurst - Guildford, Wokingham
The routeing points we will use are:
Woking (origin RP)
Wokingham (destination RP)
and the relevant fares check:
Longcross - Sandhurst SDS £7.10
Woking - Sandhurst SDS £6.70
Longcross - Wokingham SDS £5.20
showing both RPs are valid.
Mapped routes Woking - Wokingham:
LONDON PD+CS WV WW
The shortest route from Longcross - Woking is:
Longcross 0
Virginia Water 2
Chertsey 4.5
Addlestone 6
Weybridge 7.75
Byfleet & New Haw 9.25
West Byfleet 10.5
Woking 13.25
potentially also
Longcross 0
Virginia Water 1.95
Chertsey 4.45
Addlestone 5.88
Byfleet & New Haw 7.83
West Byfleet 9.11
Woking 11.77
From Wokingham - Sandhurst
Wokingham 0
Crowthorne 3.25
Sandhurst (Berks) 4.75
Outbound therefore:
Longcross - Addlestone - Woking
then
(start short at)
Woking - Guildford on map PD
Guildford - Sandhurst on map CS
All trains from Guildford to Reading between 06:13 and 08:13 inclusive call at Sandhurst. Subsequently the calling pattern is more patchy, check your chosen trains.
Using the return portion of the ticket, we will use route LONDON from Wokingham
Wokingham London Group CS+WR WV WW WX
hence
Sandhurst - Wokingham
then Wokingham - Reading - Paddington using maps CS+WR
breaking our journey at Paddington
We nominally cross London on foot/bicycle/taxi/whatever, returning to Longcross via Waterloo to Weybridge (to avoid doubling back) and then Weybridge to Virginia Water, Virginia Water to Longcross.
For 50p more you can avoid the issue of fares checks, patchy calling patterns at Sandhurst (arguably Longcross), the RG error for Longcross RPs (should be Weybridge Group in the new RG), and just buy Woking - Wokingham SDR at £8.30