Alcock arrives on the soap this evening (March 1) in the role of Mandy's mum Lorraine, who has been tipped to make life hell for the Albert Square regular in the coming days.
Speaking on ITV1's Lorraine, Alcock said that the storyline will help to show mischievous Mandy in a whole new light.
"We realise how Mandy has become like she is," the actress explained. "I think that's one of the main reasons that Lorraine has been brought to the Square.
"We've obviously seen Mandy go through hell and back. She's had her moments, and once you meet her mother, you understand how this poor girl has ended up like she is. Poor little love didn't stand a chance with a mother like me!"
Alcock also revealed that she relished the chance to portray a nasty character for the first time.
"I've had a lovely career before of playing fairly nice victims, if you like," she commented. "So this is my first stab at it. She's not quite the bitch, but there is something absolutely horrific about her.
"She does not care who she hurts or who she treads upon. She lies, cheats and manipulates - she is so manipulative, all the way through Albert Square. It's just horrendous. But brilliant to play!"
Lorraine appears on EastEnders for a few episodes before returning for another short stint later this year.
> EastEnders return for Mandy Salter's mother
> EastEnders' Mandy in turmoil over mum Lorraine - Spoiler Pictures
> EastEnders' Victoria Alcock: 'Lorraine will be a leech'
> EastEnders' Nicola Stapleton: 'Mandy may not get sympathy'
> EastEnders Mandy, Lorraine scenes are dark, says Nicola Stapleton
> Read more EastEnders spoilers and news