Official answer is no. The classical SWUs printed for use on LH cannot be printed at UA airport offices.
However, there is a rare kind of Customer Service SWUs valid on UA AND LH which can be printed on standard boarding documents by UA airport office. If you are very lucky you might get one printed without getting one deducted...
I strongly suggest to ask UA to ship certs by FedEx as all other mailings are very slow and unreliable.