With this code you have to enter 3.28, which will give you as display result : blank3.28, with other words you must use the decimal point on the keyboard.
However: if you add another line to your code, you will get the desired result and your 0328 will be displayed as 3.28 on Microfocus Cobol.
01 TEST-RECORD.
05 PR-NUM PIC 9999.
05 pr-num0 redefines pr-num pic 99v99.
05 PR-NUM1 PIC ZZ.99.
Display "Enter number"
ACCEPT PR-NUM
move PR-NUM0 to PR-NUM1
DISPLAY PR-NUM1
STOP RUN.