>>Hi Gregory,
>>
>>I've run that code, but it doesn't do what I need. I want to replace the numbers with X, e.g. the resulting string should be
>>'abcXXXXXXXXXXXXXXXXfd'
>
>Shouldn't be difficult, use option (2) slightly altered
>
So, do I understand correctly it's not easy with replace? E.g. I've tried:

if( m.loRegExp.Test(m.lcString) )
   ? 'old: ', m.lcString 
   lcString = m.loRegExp.Replace(m.lcString, '$1X{16}$3')
   
   ? 'new: ', m.lcString 
endif

but that converted the string into X{16}. I guess I can use 16X instead.

>>>&& or with Execute()
>>>lcString = 'abc1234567890123456'
>>>
>>>matchesObj = m.loRegExp.Execute(m.lcString)
>>>
>>>? 'old: ', m.lcString
>>>
>>>for i = m.matchesObj.Count - 1 to 0 step -1
>>> match = m.matchesObj.item(m.i)
>>>
>>>
>>>
>>> ?match.Submatches.Count
>>> ?match.Submatches[0]
>>> ?match.Submatches[1]
>>> ?match.Submatches[2]
>>>
>>>&& s = m.match.Submatches[0] + m.match.Submatches[1] + 'X' + match.Submatches[2]
>
>
>
> s = m.match.Submatches[0] + repl('X', len( m.match.Submatches[1] )) + m.match.Submatches[2]
>
>
>
>>> lcString = stuff(m.lcString, m.match.FirstIndex+1, m.match.Length, m.s)
>>>
>>>
>>>endfor
>>>? 'new: ', m.lcString
>>>