code:

---

Break On CLS
 
$EnumRegKey	= "HKCU\Software\Microsoft\Shared Tools\Proofing Tools\Custom Dictionaries"
$Find		= "MyCustom.dic"
 
$Index = 0
Dim $ValueName[100], $ValueData[100]
 
While @ERROR = 0
	$ValueName[$Index] = ENUMVALUE($EnumRegKey, $Index)
	$ValueData[$Index] = READVALUE($EnumRegKey, $ValueName[$Index])
	If $ValueData[$Index] = $Find $Found = 1 Endif
	If @ERROR = 0 $Index = $Index + 1 Endif
	If $Index = ubound($ValueName)
		ReDim Preserve $ValueName[$Index+100], Preserve $ValueData[$Index+100]
	Endif
Loop
 
$Index = $Index -1
ReDim Preserve $ValueName[$Index], Preserve $ValueData[$Index]
 
If Not $Found
	$nul = WRITEVALUE($EnumRegKey, val($ValueName[ubound($ValueName)])+1, $Find, "REG_SZ")
	If @ERROR
		"Error Adding: " + $Find ?
	Else
		"Added $Find to the Custom Dictionary key." ?
	Endif
Else
	$Find " is already in the Custom Dictionary key." ?
Endif

---