A S9(09)V9(02) COMP-3 field is a 6-byte PD field, but COBOL does NOT store the decimal point. 10.00 is stored as X'00000001000C'. So you need to use +1000 as the actual constant for the implied value of +10.00.
Your constant of 10 would be treated as an implied value of 0.10 which is not what you want. A constant of +10.00 would be flagged as a syntax error since a decimal point is not allowed.