Dear Sir,

I'll appreciate you very much if you can help me solve this headachy problem.

I often handle the data as the following format:
PartNo1="A"
PartNo2="B"
PartNo3="C"
.............
(Numbers of line are not fixed, more than 500 lines generally)

I want to change the number in each row as ascending or descending until the last line.But the start number is variable.
For example:

Chang to:
(Start number is 10)
PartNo10="A"
PartNo11="B"
PartNo12="C"

or
(Start number is 22)
PartNo22="A"
PartNo23="B"
PartNo24="C"