VBA Pass arguments with .onAction

I have sucessfully passed arguments with this syntax:

.OnAction = "=InsertRowWithContent(" & C & ")"

Considerations:

• C is a long. So don't add quotas, just as you wouldn't if you would call the Sub in the code.
• OnAction evaluates an expression. Therefore according to my experience, the expression needs an equal sign, and as far as I now, it must be a function. Only automated local callbacks are subs.

EDIT

My answer above has Access as background. Djikay's answer works fine with Excel. Yet after some digging, I am quiet sure that simply Word doesn't understand either of those syntaxes. Word VBA cannot pass a parameter to a sub in an OnAction statement. At least for the moment it's best to accept this.

But here is what definitively runs with Word (2010):

Create your command bar and the button. For the OnAction, only pass the name of the Sub. But use the button's Parameter property.

' Add bar
Set cdb = Application.CommandBars.Add("SomeTest", , False, False)
cdb.Visible = True

' Add button
Set cbb = cdb.Controls.Add
cbb.Caption = "PressMe"
cbb.OnAction = "TheCallback"
cbb.Parameter = 456

Then, access the parameter by the CommandBars.ActionControl.Parameter expression:

Public Sub TheCallback()

  MsgBox "The parameter passed is: " & CommandBars.ActionControl.Parameter

End Sub

ActionControl is very similar (if not the same) as ActiveControl under Access: it is the control that was clicked last.

Source: http://www.experts-exchange.com/Programming/Languages/Visual_Basic/Q_24982922.html

*phuu* :-)

You need to add a space after your Sub name, like this:

.OnAction = "'InsertRowWithContent " & C & "'"
                                  ^^^^^^^^^^

EDIT

Also, since you're passing a Long parameter, you shouldn't enclose it in quotes.

EDIT 2

OK, this will require some special sauce (code). I've been experimenting and I got the following to work.

In the Sheet1 Excel object:

Option Explicit

Sub DestroyToolbar()

  Application.CommandBars("DoomBar").Delete

End Sub

Sub MakeToolbar()

  Dim C As Long
  C = 100

  With Application
    .CommandBars.Add(Name:="DoomBar").Visible = True
    With .CommandBars("DoomBar")
      .Controls.Add Type:=msoControlButton, ID:=2950, Before:=1
      With .Controls(1)
        .OnAction = "'PressMe " & C & "'"
      End With
    End With
  End With

End Sub

In a new standard code module, add this:

Public Sub PressMe(C As Long)

  With Application.CommandBars("DoomBar")
    With .Controls(1)
      MsgBox "The value of C that was passed to this macro is: " & C
    End With
  End With

End Sub

If you run MakeToolbar, it will create a new toolbar in the "Add-ins" ribbon. To remove it, you can run DestroyToolbar.

Once the toolbar is in place, then clicking the button should display a messagebox with the value of C (in my example, 100).

I've tested the above in Excel 2010 and it worked, in a brand new .xlsm file.