It's all very well providing you a link, but the donor really could do with explaining the context.
The bit you need to study in that link concerns redeployment by the employer of redundant staff. The employer has to try to find alternative roles for redundant staff, which by saying you can't apply, your employer may not be doing. However it all depends - if the alternative role is really something you are not qualified or have the experience to do, the employer could turn you down, but it really needs to explain its reasons more fully to you.
Press the case with HR for an informal interview / or a discussion where they should explain why they are not willing to consider you.