Connect from WAN to LAN via TMG

One of my customer has a very basic setup of network with Win2k8 server with TMG installed, which has two network cards named LAN and WAN. the setup is like this;

LAN=>TMG=>WAN (Lan IP Range:10.10.10.0 - 255, TMG LAN card IP: 10.10.10.1, TMG WAN card IP: 192.168.1.10, WAN side IP Range: 192.168.1.0-255)

There is an application server in LAN side (10.10.10.111). Now somebody from WAN subnet (192.168.1.100) wants to connect to an application (could be web-base app, or normal software). So how can I configure policies/rules in TMG to allow this IP number or to an IP Range from WAN side (192.168.1.XXX) to connect to this LAN side app server (10.10.10.111)
Diagram.pdf.pdf