Improve my solution Mapping data accounting account

Hi

I have a list of account and for each i must make a translation to a specific data

For example, if the number of the account is :

between 100000 and 103999 it should be DA

between 104000 and 104999 it should be DB etc ...

for the moment i only solve by making a specfique table (Mapping) and merge it with the real account use (Cumul Balance)

It works but it is very painful

and more now I will have an additional difficulty, i must improve my table (Mapping), because now for other calculation i must check the value present in the sixth position of the account

7000010

7000020

7000030

etc

I will have to create a more complexe table.......

If you know how to do this better , thanks

Here the complete file

https://1drv.ms/u/s!AoqtZHsX4Bzvg_t_GXb7w9Yl95dpuw?e=jncqoA