An alternative suggestion is to use
http://www.gmayor.com/Envelope_Label_Add_In.htm which will print individual envelopes or labels from Excel, Outlook or typed at the keyboard, or batches of envelopes or labels from an Excel worksheet, without using mail merge. You can print as many of each label as required and start from any label.
Beware if using part used label sheets in a laser printer as some of them can get hot enough to detach labels and stick them to the drum, ruining the mechanism.