@westconn1, thank you very much. The code you provided worked perfectly. I was finally able to create the script i wanted to do ^^

That's the code for the Print function:

TEMP_PATH is a global variable containing the Path to the temp folder, where the File will be saved

Reference to "Microsoft Word __._ Object Library" is required (In my case it was 14.0)

PrintAttBox is a form I created, so the User can modify the Inputs, like the Header and the Footer

Code:
Sub PrintWithHeader(fFullPath As String)

    Dim wd As Word.Application
    Dim doc As Word.Document
    
    'MsgBox (PrintAttBox.DocName.Caption)
    
    Set wd = CreateObject("Word.Application")
    Set doc = wd.documents.Open(TEMP_PATH & PrintAttBox.DocEmail.Caption & "_" & PrintAttBox.DocPos & "_" & PrintAttBox.DocName)  'where is was saved
    With doc
        .Sections(1).Headers(1).Range.Text = PrintAttBox.DocHeader.Text
        .Sections(1).Footers(1).Range.Text = PrintAttBox.DocFooter.Text
        .PrintOut
        .Save 'if required
        .Close
    End With
    
    MsgBox ("The Document was saved successfully: " & TEMP_PATH & PrintAttBox.DocEmail.Caption & "_" & PrintAttBox.DocPos & "_" & PrintAttBox.DocName)

End Sub