The masked thug broke into the 32-year-old woman's home and demanded she hand over a four-figure sum of cash.
Tonight, a reconstruction of the horrifying robbery, which took place in a farm near Shotts, North Lanarkshire, will be shown on the BBC's Crimewatch show.
As previously reported by the Evening Times, once tied up, the gunman - who was wearing tights over his head - subjected the victim to a sexual assault.
Speaking through tears, the victim said: "I had gone into the living room and I heard a noise.
"Then the guy just appeared, then he started demanding money.
"That's when I felt the gun at the side of my head.
"It was just a nightmare. You never really think it would be something that would happen to you."
On tonight's programme, the victim's words will be spoken by an actress.
Detectives from the Specialist Crime Division will be taking part in tonight's Crimewatch appeal.
The "specifically targeted" attack took place at around 8.30am on Thursday, September 5.
Police said the suspect is described as between 5ft 8in and 5ft 10in, of stocky build, with a "noticeable beer belly".
He was wearing a khaki green army-style jumper with patches on the elbows and wearing heavy boots.
The suspect fled in a BMW car, which was found later that day abandoned near Plains, near Airdrie.
Detectives said the victim did not require hospital treatment, but had been left traumatised by her ordeal.
In November, police brought the vehicle back to the rural spot where it was abandoned in a bid to jog people's memory.
Police stopped and interviewed around 100 motorists in the Salsburgh area, where the car was abandoned, 10 weeks after the robbery.
Given the remote location, detectives have been working to establish where the suspect went after dumping the vehicle.
Detective Chief Inspector Garry Church, who is leading the investigation, said the initial appeal had a positive response from the public.
He said today: "We are now turning to Crimewatch to help to identify the man responsible for this terrifying attack on a woman in her own home.
"We are very hopeful that the reconstruction will jog someone's memory and give us the vital piece of information we require to catch the man responsible."
Police said the appeal will remain on the Crimewatch website - www.bbc.co.uk/crimewatch - until an arrest is made.
The programme is on BBC1 at 9pm.
Anyone with information on the incident is asked to contact police on 101.