Replace column value as per source excel

[ckanagala]

Hi ,

Need solution urgently .. i will explain the scenario. i am a beginner and curious to know

i have a excel source file with last week data as below

Last week:
col 1 current value previous value difference

1 100 150 -50

2. 50 75 -25

Current Week: My source excel sheet got updated as below

col1 current value

1 200

2. 150

i want output like this in Power Bi

col 1 Current value previous value difference

1 200 100 ( replace 150) 100

2 150 50 (Replace 75) 100

every week my source excel file updates with current value and in power bi my current value has to replace the previous value.

Please help me to get this logic

thanks,
Chaitanya