Measure with entered values in Report View

Dear all, 

I would like to use a measure with values that are already in a connected list and values that would need to entered in the reporting View. Is it possible to perform this with a measure?

So I have a list with 3 columns and the user needs to enter the counter values so that a Delta Value can be calculated:

Delta = Root (( A - A')^2) + (( B - B')^2 )+ (( C - C')^2))

Values marked with ' are the ones that need to be entered by the user. 

I appreciate any recommendations and support. Thank you

Best regards

Julia