Using a repeater on a DSL modem

Hello, I'm new to the forum. I have been lurking and since I now have my own problem, I decided to register to get some help.
Let me know if this can be done.
I have Qwest DSL Internet, with an Actiontec Q1000 Modem. I also have a D-Link DWL-2100AP that I was using as a repeater on my old ISP. Can I still use the DWL-2100AP as a repeater on my DSL network? If so, how, as I'm confused on the security set-up?

I tried and selected "AP Repeater" on the D-link, hit scan, saw my network, selected it and the proper fields propagated with my network info, but I'm confused about the security. The only authentication types available are "Open System" and "Shared Key", and I don't know enough about security to know what I need to select. My modem has a 26 character security key/passphrase, and don't know how many bits that relates to. The options there are 64 Bit, 128 Bit, and 152 Bits. The qwest modem is set up for WPA/WPA2 PSK security type, but I only get that option if I select another mode for the D-link, like access point. Does the authentication type matter?

If I can't use repeater mode, can I use Access Point mode, or another mode on the D-link, to have it work with my new ISP (DSL) set-up?

Thanks for the help.

Rick