Custom weapons, by default, don't work with melee attacks. To fix this you must make your own patch.
To make a custom patch you need these applications:
MyWarcraftStudio (http://www.mediafire.com/?b75gin2bg5kn6qw)
CSVed (http://home.hccnet.nl/s.j.francke/csved/csvedsetup.exe)
DBCUtil (http://www.mediafire.com/?iksn17av9j3b9hv)
First you need to extract the dbc files from WoW. To do this, download this http://hosted.antithesisgames.com/wow/mpqe_cpp.rar.
Extract the rar file and put the files in your wow folder -> Data -> enUS. After you do this, open extractdbc.bat
After it completes extracting the dbc files, drag item.dbc to DBCUtil.exe. It will make a file called Item.dbc.csv.
Delete the file Item.dbc.
Open Item.dbc.csv using CSVed. Go all the way to the bottom, right click and go to Add Record.
A window will pop up, showing columns.
Put this in the column entries:
Column 1: Item entry id
Column 2: Item Class
Column 3: Item SubClass
Column 4: Set to -1
Column 5: Quality of item
Column 6: Display ID of item
Column 7: Inventory ID
Column 8: Set to 0
Column 9: Ignore this
Repeat for all other items, then save the file.
After saving the file, drag the csv file to DBCUtil.exe, it will then make a file named Item.dbc.
Create a folder named DBFilesClient, put Item.dbc into that folder.
Open the program MyWarcraftStudio. Click on Pack(P) then click on Create MPQ Archive.
Name the MPQ file patch-A.MPQ.
Right click in the white space and then Import Folder. Navigate to the folder you created. Open Item.dbc.
After you do that go back to Pack(P) and click on Save and Close Archive.
You now have your patch file! Put the patch in your Wow Folder->Data.
Distribute to all users.