|I'm not sure I'm supposed to answer my own questions, but:|
In the "Click()" function for the button:
DoCmd.OpenForm "FormName", acNormal, "", "", , acNormal, Me.IDToPass
and, in the form that is being opened's "Current()" function:
Me.IDToSet.Value = Form.OpenArgs
Hope this can help somebody else!
Can I put a question here?