access table transpose two fields

Hello,
It's not easy for me to describe what I want. :-)

I have a database table with two fields. In one field is an Active Directory Group, in the other field are the member of the group. In some groups there are 300 to 700 users separated by a semicolon. But now I want to split the users into a column representation.

What I have:

group member
group1 abc@domain.de;def@dom@domain.de;ghi@domain.de;jkl@domain.de;nop@domain.de;.....
group2 aaa@domain.de;bbb@domain.de;ccc@domain.de;ddd@domain.de;...
group3 ...

What I need:

group1 abc@domain.de
group1 def@domain.de
group1 ghi@domain.de
group1 jkl@domain.de
.
.
.
group2 aaa@domain.de
group2 bbb@domain.de

How can I do this best and easily?

Best regards Andreas