When editing the toolbar button or hotkey, set the Function drop-down to Script Function.
In Opus 12 or above, set the Language drop-down to VBScript.
(If using Opus 11 instead, add an extra line with @script VBScript to what's below.)
Paste this code into the large, main field in the button editor:
Option Explicit
Function OnClick(ByRef ClickData)
Dim fso, tfile, txt
Set fso = CreateObject("Scripting.FileSystemObject")
Set tfile = fso.OpenTextFile("p:\directory\filename.txt")
txt = tfile.ReadAll
DOpus.SetClip txt
End Function
That will read p:\directory\filename.txt into memory and put the text into the clipboard.
You could turn the script into a Script Add-In which adds a command you can use like that in other buttons. (The command would have to have a different name, since there's already a Clipboard command, but apart from that it could work exactly as you want.)
To get you started, here is the updated code that will copy content of any selected file to clipboard
Option Explicit
Function OnClick(ByRef ClickData)
Dim fso, tfile, txt
If ClickData.func.sourcetab.selected_files.Count > 0 Then
Set fso = CreateObject("Scripting.FileSystemObject")
Set tfile = fso.OpenTextFile(ClickData.func.sourcetab.selected_files(0))
txt = tfile.ReadAll
DOpus.SetClip txt
End If
End Function
[Script code updated, as per the next post below. --Leo]