Binding text boxes and string dynamically in asp.net using placeholder -

i have following code in im using place holder hold dynamically created text boxes. pre init , loadviewstate overridden facilitate changes, method nextid incriment id 1 , render back. create method create new instance of textbox , add list.

my question can replace "#" in string str textbox , rest of string should appended , on final ui user should see textboxes instead of "#" , other string values is. im sorry if question seems irrelevant, im newbie......any appreciated, thanks

public partial class _default : system.web.ui.page {  public void create() {         textbox txt = new textbox();         txt.id = "txtfillup" + nextid.tostring();         dynamiccontrol.controls.add(txt);         //dynamiccontrol.controls.add(new literalcontrol("<br>"));         controllist.add(txt.id); }  public list<string> controllist {         {         if (viewstate["controls"] == null)         {             viewstate["controls"] = new list<string>();         }         return (list<string>)viewstate["controls"];     } }   public string str = "# capital of #";  stringbuilder sb = new stringbuilder();  public int nextid {         {         return controllist.count + 1;     } }  protected override void onpreinit(eventargs e) {     base.onpreinit(e); }  protected override void loadviewstate(object savedstate) {     base.loadviewstate(savedstate);     foreach (string s in controllist)     {         textbox txt = new textbox();         txt.id = s;         dynamiccontrol.controls.add(txt);         //dynamiccontrol.controls.add(new literalcontrol("<br>"));     } }   protected void page_load(object sender, eventargs e) {     foreach (char s in str)     {         if(s == '#')         {            create();//replace "#" textbox in string str.         }         else         {             //if chaacterr not "#"  should appended is.         }     }     dynamiccontrol.controls.add(//adding modified string displayed in ui); }