Find and replace in string re.insensitive

I have this code to find matches in a string, im using in a search to mark the wordds that match my search, i need this to be case insensitive, the issue here is that it replaces the word by the one we search.

val_to_searchp = "this Text string has alot of teXt"
word = "TEXT"
    
pal2rep = str(":::")+word+str(":::")
val_to_search = re.sub(re.escape(word), pal2rep, val_to_searchp, flags=re.IGNORECASE)

this will return

"this :::TEXT::: string has alot of :::TEXT:::"

I need it to return

"this :::Text::: string has alot of :::teXt:::"

Also tryed with this but its not working very well 🙁

f = 0
s = 0
val_to_search = val_to_searchp
for m in re.finditer(str(word), str(val_to_searchp)):
      inicio = int(m.start()+s)
      fim = int(m.end()+f)
                
      val_to_search = val_to_search[:inicio] \
             + str(":::") \
             + val_to_search[inicio:fim] \
             + str(":::") \
             + val_to_search[fim:].strip()

      f = f+2
      s = s+1

This is my actuall code

def findtext():
    if len(str(findtext_inp.get('1.0', END)))>1:
        val_to_searchp = str(respon_txt.get(1.0, END).replace(html.unescape('⛔'), "").strip())
        respon_txt.delete(1.0, END)
        word = str(findtext_inp.get('1.0', END).strip())

        pal2rep = str(str(html.unescape('⛔'))+word+str(html.unescape('⛔')))
        val_to_search = re.sub(re.escape(word), pal2rep, val_to_searchp, flags=re.IGNORECASE)


        """
        f = 0
        s = 0
        for m in re.finditer(str(word), str(val_to_search)):
            inicio = int(m.start()+s)
            fim = int(m.end()+f)
        
            val_to_search = val_to_search[:inicio] \
                + str(html.unescape('⛔')) \
                + val_to_search[inicio:fim] \
                + str(html.unescape('⛔')) \
                + val_to_search[fim:].strip()

            f = f+2
            s = s+1
        """


    respon_txt.insert(1.0, val_to_search)#val_to_search.replace(findtext_inp.get('1.0', END).strip() , str(html.unescape('⛔')+findtext_inp.get('1.0', END).strip())+html.unescape('⛔')))

>Solution :

I’m sure there’s a way to do this with RE but it’s really trivial without the aid of that module.

val_to_searchp = "this Text string has alot of teXt"
text = 'TEXT'

def func(s, txt):
    txt = txt.lower()
    for i, e in enumerate(t := s.split()):
        if e.lower() == txt:
            t[i] = f':::{e}:::'
    return ' '.join(t)

print(func(val_to_searchp, text))

Output:

this :::Text::: string has alot of :::teXt:::