Practice_customLookupPage

<apex:page controller="Practice_customLookupPageController" id="wpage">
<script type="text/javascript">
var templatenameid;
function openTemplatePopUp(field){
    var anchortagid=field.id;
    var rowindex=anchortagid.substring(9,10);
    templatenameid='wpage:form1:pgb1:pgbks1:pgbsi1:pgbt1:'+rowindex+':Template';
    //alert('--anchortagid:'+anchortagid+';--templatenameid:'+templatenameid);
    if (field != null) {
        field.href = "JavaScript:openLookup('/_ui/common/data/LookupPage?lkfm=editPage&lknm='+templatenameid+'&lkrf=&epf=1&lktp=00X',670,'1','&lksrch=' + escapeUTF(getElementByIdCS(templatenameid).value.substring(0, 80)))";
    }
}
</script>
<apex:form id="form1">
   <apex:pageBlock title="Custom lookup" id="pgb1">
       <apex:pageblockSection id="pgbks1" columns="2">
           <apex:pageBlockSectionItem id="pgbsi1">
               <apex:pageblockTable value="{!recordsList}" var="rec" id="pgbt1">
                   <apex:column headerValue="Email Template">
                       <div> 
                            <apex:inputhidden value="{!rec.emailTemplateId}" id="Template_lkid" />                 
                            <apex:inputhidden value="{!rec.emailTemplateName}" id="Template_lkold" /> 
                            <span class="lookupInput"> 
                                <apex:inputText value="{!rec.emailTemplateName}" onchange="getElementByIdCS('wpage:form1:pgb1:pgbks1:pgbsi1:pgbt1:{!rec.counter}:Template_lkid').value=''; " id="Template"/>                   
                                <a title="Email Template Lookup (New Window)" tabindex="4" onclick="setLastMousePosition(event),openTemplatePopUp(this)" id="Template_{!rec.counter}_lkwgt" >
                                    <img title="Email Template Lookup (New Window)" onmouseover="this.className = 'lookupIconOn';this.className = 'lookupIconOn';" onmouseout="this.className = 'lookupIcon';this.className = 'lookupIcon';" onfocus="this.className = 'lookupIconOn';" onblur="this.className = 'lookupIcon';" class="lookupIcon" alt="Email Template Lookup (New Window)" src="/s.gif" />
                                </a>
                            </span>
                       </div>
                   </apex:column>
                   <apex:column headerValue="Frequency">
                       <apex:selectList value="{!rec.frequency}" size="1" >
                           <apex:selectOption itemLabel="Daily" itemValue="Daily"/>
                           <apex:selectOption itemLabel="Weekly" itemValue="Weekly"/>
                           <apex:selectOption itemLabel="Monthly" itemValue="Monthly"/>
                       </apex:selectList>
                   </apex:column>
               </apex:pageblockTable>
           </apex:pageBlockSectionItem>
       </apex:pageblockSection>
   </apex:pageBlock> 
</apex:form>
</apex:page>

Practice_customLookupPageController

public class Practice_customLookupPageController {
    public List<emailTemplateWrapper> recordsList{get;set;}
    public Practice_customLookupPageController (){
        recordsList=new List<emailTemplateWrapper>();
        recordsList.add(new emailTemplateWrapper(0));
        recordsList.add(new emailTemplateWrapper(1));
        recordsList.add(new emailTemplateWrapper(2));
    }
    public class emailTemplateWrapper{
       public String emailTemplateName{get;set;} 
       public String emailTemplateId{get;set;}
       public String frequency{get;set;}
       public integer counter{get;set;} //to store rowindex
       public emailTemplateWrapper( integer count){
           frequency='Weekly';
           counter=count;
       } 
    }
}