Split worksheets

Hi Guys,
Need a bit of help please:
In column A of a spread sheet I have lots of entries in this format:

admin_staff_a_002
admin_staff_a_006
admin_staff_1_010
admin_staff_1_003
admin_staff_b_005
admin_staff_z_007
admin_staff_z_001


What I need to achieve is to have a different worksheet containing all the rows for admin_staff_a then another for admin_staff_1 etc.

I want to name each of the worksheets a, 1 etc so i'd remove the admin_staff bit and the _003 bit

Not sure if I'm being clear enough but its hard to describe!

Thanks