I don't know what ELNK is.
Some cable ISPs maintain a dialup number. Many don't... you would have to check with them to see if that option exists.
Just the same, you can configure your options to do dialup, cable, wireless, etc. There's a few little issues about where 'read' mail goes to and that stuff but sure, you can dialup to NetZero (and pay separately for that account) with or without the cable connection. You need a phone line to bypass the cable modem but its all there in the configuration menus.
I tote around a laptop in my work and on any given day I might have to select cable, wireless or dialup. Never had any issues. Biggest issue is the anti-virus software that will start downloading shit immediately when you get online and bog down the overall speed maybe for a few minutes (AVG) .
-Bill