[Koha] subfields

Hi everyone, I'm having this problem. in the author field I have the first and last name in different subfields and when I use the editmarc to change it it deletes the nickname, I just want it to look like this = 100\\$aTrevisa, Dalton not this =100 \\$aTrevisan$bDalton in field 260 I want to do the opposite. add the subfields to stay like this = 260 \\$aPraia$bCape Verde Bank$c2015 but i have this=260 \\$aPraia: Banco de Cabo Verde, 2015 Can someone help me? Ana Bela