Hi Frank,
Am not sure this will help you or not.
If you set specific key figure properties decimals as you said 2, then you check Excel cell/column where 0RECTOTSTCK value displayed on bex report out. select perticular cell from that column where no data was there on sheet, right click on cell(where there is no data, as show block rectangular)-->format cells. you will get below screen, click on number or currency and if decimals are 0 then change to 2.
just have a try.
Thanks