Voltemand appears as a minor character in [William Shakespeare]'s famous play [Hamlet]. King [Claudius] of [Denmark] sends Voltemand and [Cornelius] to deliver a message to the nephew of the King of Norway, [Fortinbras], who is running the country while the king is sick. Fortinbras wants to attack Denmark, and [diplomacy] is called to the front.

KING CLAUDIUS:
The lists and full proportions, are all made
Out of his subject: and we here dispatch
You, good Cornelius, and you, [Voltimand],
For bearers of this greeting to old Norway;
Giving to you no further personal power
To business with the king, more than the scope
Of these delated articles allow.
Farewell, and let your haste commend your duty.
-- [Hamlet I.ii]

He makes a second appearance later, returning with Fortinbras' reply, a long and [courtly] letter from the King saying that there will be no war. This is Voltimand's only speaking part in the play.

VOLTIMAND:
Most fair return of greetings and desires.
Upon our first, he sent out to suppress
His nephew's levies; which to him appear'd
To be a preparation 'gainst the Polack;
But, better look'd into, he truly found
It was against your highness: whereat grieved,
That so his sickness, age and impotence
Was falsely borne in hand, sends out arrests
On Fortinbras; which he, in brief, obeys;
Receives rebuke from Norway, and in fine
Makes vow before his uncle never more
To give the assay of arms against your majesty.
Whereon old Norway, overcome with joy,
Gives him three thousand crowns in annual fee
, And his commission to employ those soldiers,
So levied as before, against the Polack:
With an entreaty, herein further shown,
Giving a paper
That it might please you to give quiet pass
Through your dominions for this enterprise,
On such regards of safety and allowance
As therein are set down.
-- [Hamlet II.ii]

Voltimand mostly makes it into scholarly papers (if he makes it at all) because Shakespeare was very careless with the names of his minor characters. Voltimand's name is given variously as Voltemand ([F1]), Voltimand ([F2]), Valtemand ([Q2]), Voltumand (F1), and Voltemar ([Q1]). (The Qs and Fs refer to Shakespeare's two [quarto] editions and his two [folio]s. Modern editors have taken the 'best' from these various versions and pieced together the Hamlet we are familiar with.)

All of these are probably based on the Danish name [Valdemar], which was the name of a set of Danish kings and of an uncounted number of Danish commoners. It is unknown if Shakespeare was intentionally changing the name or if he just didn't care. It is also possible that he intended to write Valdemare, but poor handwriting led a scribe to copy it as Valdemand, a mistake that spread throughout the other versions of the play.

References:
http://hudsonshakespeare.org/Shakespeare%20Library/Character%20Directory/CD_Hamlet.htm
[The Manuscript of Shakespeare'S Hamlet and the Problems of its Transmission] by J. Dover Wilson.
http://cla.calpoly.edu/~dschwart/engl339/hamlettext.html#hamletf1
And [Hamlet|http://everything2.com/title/Hamlet], of course.

Voltimand (person)