Please Help - Is there a DAX or M code for this????

Hi again, so I actually need this to be in M. Is that possible?

I desperately need to figure this out for my work.

Here's the overview:

I have a table , named 'Future Date Service Agreement Plans (3)' with two columns that are giving me trouble. They are called:

[Total_Remaining_Cost__c] 

and 

[Daily_Rate_Based_On_Days_Remaining__c]

Both of these columns repeat the same number over and over again until another dimension in the table [Account Name] changes, then they repeat the process. 

Would I would like for them to do is subtract the [Daily_Rate_Based_On_Days_Remaining__c] from the [Total_Remaining_Cost__c]  and the have the [Total_Remaining_Cost__c] column go down with each day. So, it would look just as yours did at the start, only it would need to start over with each [Account ID] change (Which happens when the date in the Day By Day column reaches the date in the EndDate column.

Here's a picture of what the table currently looks like.