For question 1, it sounds like you just want to replace whatever is in the third digit after the decimal point with a blank. You can use these DFSORT control statements to do that where c is the starting position of your 10 byte field + 9 (e.g. if your field starts in position 11, c is 20):
This overlays the third digit with a blank.
For question 2, it sounds like you just want to replace the blank in the third digit with a '0'. That would be: