shopt -s expand_aliases # turn on alias support in noninteractive shell
# define the function
alias_git_as() { alias "git_as_$1=GIT_AUTHOR_NAME=${2@Q} GIT_AUTHOR_EMAIL=${3@Q}"; }
# use the function
alias_git_as "login" "Surname Prename" "user@company.de"
# use the invoked alias
git_as_login
declare -p GIT_AUTHOR_NAME GIT_AUTHOR_EMAIL
alias -p
c2hvcHQgLXMgZXhwYW5kX2FsaWFzZXMgIyB0dXJuIG9uIGFsaWFzIHN1cHBvcnQgaW4gbm9uaW50ZXJhY3RpdmUgc2hlbGwKCiMgZGVmaW5lIHRoZSBmdW5jdGlvbgphbGlhc19naXRfYXMoKSB7IGFsaWFzICJnaXRfYXNfJDE9R0lUX0FVVEhPUl9OQU1FPSR7MkBRfSBHSVRfQVVUSE9SX0VNQUlMPSR7M0BRfSI7IH0KCiMgdXNlIHRoZSBmdW5jdGlvbgphbGlhc19naXRfYXMgImxvZ2luIiAiU3VybmFtZSBQcmVuYW1lIiAidXNlckBjb21wYW55LmRlIgoKIyB1c2UgdGhlIGludm9rZWQgYWxpYXMKZ2l0X2FzX2xvZ2luCgpkZWNsYXJlIC1wIEdJVF9BVVRIT1JfTkFNRSBHSVRfQVVUSE9SX0VNQUlMCmFsaWFzIC1w