Excel formula solver

dear all

i am looking up for a help. Let me describe the situation

 

in sheet A, I have 300 values from A1 to A300. in sheet2 i have a spreadsheet what calculates output,  from A1 to A300 but only one value in one time

 

how to create a solver, code, function which will send value f.e. from a1 as input to my spreadsheet and returns value as result to b1, afterwards i want to send a2 value as input into spreadsheet and return the result to b2. and do the same up to a300

 

thanks