I need to help my daughter move all of her Yahoo emaill addresses to Comcast. She uses Windows 98 SE if that matters. I use Windows XP Home.

I used my Yahoo as a test to see how it works but I cannot move the yahoo addresses. I did an export from Yahoo as a Windows CSV and saved the file to my desktop and went into my Comcast account to import them. The only information it brought in was unknown.
She only uses email on the internet so using Outlook etc. is not an option.
Can anyone suggest how I can move these Yahoo addresses to Comcast.

Thanks in advance.