Code:
strDomainName = "NetBIOS Domain Name"

ADname = GetfullName("SamAccountName")

Function GetFullName(strNT4Name)
On Error Resume Next
Err.Clear

	Set objTrans = CreateObject("NameTranslate")
	objTrans.Init 3, ""
	objTrans.Set  3, strDomainName & "\" & strNT4Name
	GetFullName = objTrans.Get(1)

End Function


this is VBscript to get a distinguished name from a SamAccountName. Let me know if you need any help to convert it