Dim As String table = "Add ALTer  BAckup Bottom  CAppend Change SCHANGE  CInsert CLAst COMPress COpy " _
+ "COUnt COVerlay CURsor DELete CDelete Down DUPlicate Xedit EXPand EXTract Find " _
+ "NFind NFINDUp NFUp CFind FINdup FUp FOrward GET Help HEXType Input POWerinput " _
+ "Join SPlit SPLTJOIN  LOAD  Locate CLocate  LOWercase UPPercase  LPrefix MACRO " _
+ "MErge MODify MOve MSG Next Overlay PARSE PREServe PURge PUT PUTD  Query  QUIT " _
+ "READ  RECover REFRESH RENum REPeat  Replace CReplace  RESet  RESTore  RGTLEFT " _
+ "RIght LEft  SAVE  SET SHift SI  SORT  SOS  STAck STATus  TOP TRAnsfer Type Up"

Function NextWord(Byref posic As Integer, text As String) As String
    ' skip spaces
    While posic <= Len(text) And Mid(text, posic, 1) = " "
        posic += 1
    Wend
    ' get the word
    Dim word As String = ""
    While posic <= Len(text) And Mid(text, posic, 1) <> " "
        word += Mid(text, posic, 1)
        posic += 1
    Wend
    Return word
End Function

Function MinABLength(comando As String) As Integer
    Dim ab_min As Integer = 1
    While ab_min <= Len(comando) And Ucase(Mid(comando, ab_min, 1)) = Mid(comando, ab_min, 1)
        ab_min += 1
    Wend
    Return ab_min - 1
End Function

Function Expand(table As String, word As String) As String
    If Len(word) = 0 Then
        Return ""
    Else
        Dim As Integer word_len = Len(word)
        Dim As String result = "*error*"
        Dim As Integer posic = 1
        Do
            Dim As String comando = NextWord(posic, table)
            If Len(comando) = 0 Then
                Exit Do
            Elseif word_len < MinABLength(comando) Or word_len > Len(comando) Then
                Continue Do
            Elseif Ucase(word) = Ucase(Left(comando, word_len)) Then
                result = Ucase(comando)
                Exit Do
            End If
        Loop
        Return result
    End If
End Function

Sub TestExpand(words As String, table As String)
    Dim As String word, results = "", separator = ""
    Dim As Integer posic = 1
    Do
        word = NextWord(posic, words)
        If Len(word) = 0 Then Exit Do
        results += separator + Expand(table, word)
        separator = " "
    Loop
    Print "Input:  "; words
    Print "Output: "; results
End Sub

' task test cases
TestExpand("riG   rePEAT copies  put mo   rest    types   fup.    6       poweRin", table)
TestExpand("", table)

Sleep