I see Antonio answered

It's basically expanding the second part between parentheses

Also, if the number of digits can be different, say from one to 4

function do_it()
	
	local regexObj
	regexObj = createobject('VBScript.RegExp')
	regexObj.Global = .t.
	regexObj.IgnoreCase = .f.
	regexObj.Pattern = '(\[\d{1,4})([\x21-\x2f\x7b-\x7f])(\d{1,4}\])'
	
	local s, x
	s ='1st-title: ANAME-HER : 3520931 place[1~4444]'
	?s
	x = m.regexObj.Replace(m.s, '$1.$3')
	?x
	
endfunc
*_______________________________________________________________________________

>many thanks for all the suggestions. I will spend the day today trying the solutions out and see how far I get.
>
>greg - is there a way in your pattern to keep the hyphen (-) open to any character - it could end up being :~+= (I never what what's coming down the pipe - I anticipate most of the time the error will be in the form of a hyphen that I need to convert back to a dot. Perhaps an asc that covers all chr from 1-49 before the numbers start. so asc(1..49) in lieu of (-) I don't know how that would be represented in code or if it is even possible.
>regexObj.Pattern = '(\[\d\d)(-)(\d\d\])'
>
>thanks
>k
>
>>>I am searching for the most expedient way to change a character in a specific area of a string.
>>>
>>>mstr='1st-title: ANAME-HER : 3520931 place[21-22]'
>>>in this string the hyphen between 21 and 22 should be a dot.
>>>if I applied chrtran() I would end up changing all the hyphens which I do not want to do.
>>>
>>>right now all I've been able to accomplish is to locate the error in a portion of the string, but putting it back together is starting to get a bit unwieldy.
>>>Is there a simpler more direct route of directing the chrtran() to the area beyond '['
>>>
>>>thanks
>>>k
>>Karen,
>>
>>If you have been able to locate the error portion, use something like
>>

>> substr(mstr,1 , pos-1) + '.' + substr(mstr, pos+1)
>>

>>
>>Also, if
>>(1) [ followed by two digits are immediately before the hyphen, and
>>(2) two digits and ] immediately follow the hyphen
>>
>>Then regular expressions may be of help
>>
>>

>>*_______________________________________________________________________________
>>function do_it()
>>	
>>	local regexObj
>>	regexObj = createobject('VBScript.RegExp')
>>	regexObj.Global = .t.
>>	regexObj.IgnoreCase = .f.
>>	regexObj.Pattern = '(\[\d\d)(-)(\d\d\])'
>>	
>>	local s, x
>>	s ='1st-title: ANAME-HER : 3520931 place[21-22]'
>>	?s
>>	x = m.regexObj.Replace(m.s, '$1.$3')
>>	?x
>>	
>>endfunc
>>*_______________________________________________________________________________
>>