sql: updating comma separator values -

i looking answer can directly update comma separated values without splitting comma values.

for example:

old value   new value 123     111 234     222 345     333 456     444 

current

id  value 1   123,345 2   123 3   345,456,234 

expected

id  value 1   111,333 2   111 3   333,444,222 

i have used logic of splitting comma values updating new values , @ last using coalesce club new values comma separator. since count big logic taking lots of time execution.

can please suggest me better solution this?