Hi OctavioCunha-8450 I want to help you with this question.
If I understand you right, you want to have a user principal who has the privilege to act on behalf of another user.
If the identity of (admin A) could be another EA app in the AzureAD, then you are able to act on behalf of another user in application B and get the user token.
I make a quick search and found the following, related thread: https://stackoverflow.com/questions/74516076/how-to-impersonate-user-of-other-azure-ad-app
Maybe it helps you in your scenario too.
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