I have a problem which is simple (I guess) but I don't know how to solve it :(

I have the following (current) Data:

current

goal

result

750

750

750

-700

-700

50

-375

-50

0

125

125

125

-250

-125

0

750

750

750

-750

-750

0

I need KNIME to calculate from the "current" data the goal and the result column. The result column can be easily calculated from the goal column. It is important, that the values in the result column never reach below 0, therefore I need to have a adjusted goal column. The calculation in the result column is just an addition of the previos row in the result column with the current row in the goal column.

Iris' suggestions will work only if the input contains both the current and goal values.

Since the calculation for a row depends on the calculation in the previous row, a recursive loop will do the trick.
In the attached workflow, the upper branch calculates the goal and result values for each row. The result of each row is fed back for use in the next iteration, along with the unaltered remaining rows of the input table.

There are other ways to do this, but this workflow gives the desired output using only the current values as input. Hope this helps.