I believe this will work for you with X-Mouse Button Control (XMBC):
(1) select the Layer 1 tab within the XMBC software;
(2) you can name Layer 1 in its title box if you like but it's not required;
(3) then beside Left Button select its drop down menu and with it select Button Held Custom;
(4) then to the right of this same drop down menu is a small square button, select it and a window titled "Button Held Time Dependent Actions" will open. It's within this BHTDA window you'll create a press & hold time for this Left Button so that when it's held down for that long (say 500 milliseconds), that button will automatically perform a "double click" at that moment just as if you actually had double-clicked your left mouse button;
(5) Now, in this BHTDA window (you can enter a name in it for this customization if you want but it's not required) to the right of the words "Normal Click" is a drop down menu; it it select Left Click;
(6) In the next row down mouse-click the box next to "Held for" then to the right set your hold-down time (or use the default time that's already typed in there--you can modify it again later if you want to change it)... then a bit further right is a drop down menu--in it select "Double Click";
(7) now at the bottom of the BHTDA window select the OK button and the BHTDA windows closes;
(8) now you're back in the main window, press its Apply Button, then press its Close Button and your done!
I hope my directions are clear because I just ran out of time for this task. I'm sure this description should clear all this up for you in so far as gaining a basic understanding of how to use this mouse software.