How to parse a text file in ASP?

[ghostface]

**How do I parse a textfile and edit only a certain part of it. Specifically, just the
last column. My textfile looks like this.

#Server Group 1
!Name01,192.168.2.201,5901,123456,description01,\\ p4d1,01,on
!Name02,192.168.2.202,5902,123456,description02,\\ p4d1,01,on

**Now I have an ASP page with buttons.
**example.
**When I click button1.. It means it will parse row 1 and last column. Changing
**the "on" to "off". The text file should look like this.

#Server Group 1
!Name01,192.168.2.201,5901,123456,description01,\\ p4d1,01,off
!Name02,192.168.2.202,5902,123456,description02,\\ p4d1,01,on

**When I click button2.. It will parse row 2 and last column. The text file should
**look like this.

#Server Group 1
!Name01,192.168.2.201,5901,123456,description01,\\ p4d1,01,on
!Name02,192.168.2.202,5902,123456,description02,\\ p4d1,01,off

**I need to Identify the row number, parse the textfile, edit the last column.
**Any suggestions will definitely help.. Thank you.. =)