I have monitor (DELL U2713HM) with WQHD resolution (2560x1440) and he support full resolution by DVI-D and DisplayPort and there is problem but in my laptop (MSI GE60) support this resolution only on HDMI port. I would to ask You: Can I convert HDMI on DVI-D or DisplayPort without losing WQHD resolution?
HDMI and DVI-D are electrically compatible. The main exceptions for regular computer use are that HDMI supports audio (which DVI doesn't, and your laptop's output may or may not provide), and DVI allows for an analog link (which HDMI doesn't). Neither should be a significant issue in your case. It also appears that some graphics cards might not be able to drive all digital ports simultaneously and require an active converter, but that shouldn't be a problem either since it sounds like you are just looking to hook up a single external monitor to your laptop.
Going from HDMI to DVI-D (or the other way around) thus only requires a passive adapter cable or something similar. These are available at the few dollars/euros/pounds price point for a basic one, with prices going up if you want something fancy like gold-plated contacts.
Do however make sure that you get a converter that has "dual link" at the DVI-D side. Dual link is required to support higher resolutions over DVI; specifically, anything higher than 1920 x 1200 at 60 Hz. Dual link DVI-D allows up to 2560 x 1600 at a 60 Hz refresh rate, which meets your requirement of supporting 2560 x 1440.
I'm personally running (since a week ago) a Dell U2412M through the monitor's DVI-D input on the graphics card's HDMI output, with only a passive adapter cable. Works like a charm so far, with no discernable problems.