Freeze numbering when sorting

[Or Freund]

I have Table like this :
Num Name LastName
1 Or Freund
2 Someone SomeGuy
3 First Last

and I want to sort it buy Last Name so but keep the same numbering so the
result will be like this :
Num Name LastName
1 Or Freund
3 First Last
2 Someone SomeGuy

and not like this :
Num Name LastName
1 Or Freund
2 First Last
3 Someone SomeGuy

the numbering column is automatic , is there any way to make it "freeze" ?

Thanks
Or.