I find that the best way to create "x" in Hero Lab is to copy "y" and then modify it to suit my needs. So in a case like this, I might open up the editor (Tools=>Show Editor) and then create a new data file (unless you have one for your game already). Hopefully, you know all of these steps already and you already have some skills with the editing tools in Hero Lab!
The real key here is that you want a weapon that will deal both ranged damage as a bow as well as a melée weapon. For S&Gs, I might copy a dagger for this pupose because it does both kinds of damage; you might copy something else as you see fit, but just run with me for a few minutes…
With my copied "Dagger," I'll rename it, add a new description. Now comes the heavy lifting:
- Start going through the tag editors one by one and make changes:
- Damage Type (Go through all of the options!)
- Profiency requirement
- Category (you didn't mention this, for instance, but does your weapon have reach? Is it s "double weapon" with a blade at both ends?)
- Mess around with the properties
- Adjust the range
- …and so on.
I won't write the weapon for you; I encourage you to experiment and play with the settings. If you get stuck, look at how a weapon with similar properties is tagged (thus, how does that long bow consume ammunition?). If it completely screws up your character, just delete the weapon and start over—there's only about a dozen steps to any given object! And if you're still feeling stuck, head over to the forums at Lone Wolf. The community there is very helpful at assisting newbies attempting to learn their product's syntax.
I sincerly hope this helps and gives you the confidence to just experiment!