Flood is currently Disability Awareness in Action information and publications co-ordinator, a role she will keep for one day a week.
She joins Scope on 18 April in a newly created post that was only open to disabled applicants.
She will represent the public policy and campaigning positions of the charity, whose profile has surged via its 'Time to Get Equal' campaign.
Scope, historically the charity for cerebral palsy, is recruiting disabled people to its own ranks in recognition 'that it has not been practising what it preaches'.
Of 28 senior posts, a quarter will be filled by disabled people by July; by 2007 it wants disabled people to represent at least 20 per cent of its 4,000-strong workforce.
Scope's first post reserved for a disabled person was that of executive director of diversity and corporate planning, claimed by Andy Rickell 11 months ago.
Flood told PRWeek: 'Ordinarily I have a problem with positive discrimination, and no doubt I will face this kind of accusation. But it was a robust interview process and I believe I have been taken on for my skills first and foremost.'
Scope has split its 31-strong comms team from its 13-strong marketing operation and has promoted equality campaigns manager Louis High to the new role of head of comms and campaigns.
Pauline Simpson remains executive director for marketing; Ben Sear becomes head of marketing, a change from his former role as head of marketing and comms.
The 1995 Disability Discrimination Act does not prevent posts being advertised as open only to disabled applicants, or an applicant being preferred due to his or her disability.