Hi, Toghraee,
On DQ77KB, eDP shares the LVDS port, so whatever you set LVDS in the BIOS affects eDP as well.
Intel has posted instructions on building an eDP to DP cable in the whitepaper on validating eDP:
http://www.intel.com/content/dam/www/public/us/en/documents/white-papers/validation-methodology-paper.pdf. Refer to pages 12-13 under the section "HW and SW Uniqueness". I believe this is what you are looking for. Let us know if you have any issues accessing the above link.
Craig