I have a formula that works well, it is written to replace a section of data in a cell. it is =REPLACE(F3, 8, 1,1) =REPLACE(Cell range to evaluate , where to start, how many to replace , what to replace with )

I need to run this formula down an entire range of cells, and I want it to ignore any cell that is blank. I'm not sure how to combine the isblank function with the above formula to get the desired result.
can somebody help me ?