I just wanted to make sure that you were talking about a product page , the solution will probably be to edit the "quantity" file of the "product" view of your front-end template through "Hikashop->Display->Views" and change these lines :
if($this->row->product_quantity==-1){
?>
<div class="hikashop_product_stock">
<?php
if($this->params->get('add_to_cart',1)){
echo $this->cart->displayButton(JText::_('ADD_TO_CART'),'add',$this->params,$url,$this->ajax,'',$max,$min);
$btnType = 'wish';
}
if(hikashop_level(1) && $this->params->get('add_to_wishlist') && $wishlistEnabled && !$hideForGuest && $this->config->get('display_add_to_wishlist_for_free_products','1')){
echo '<div id="hikashop_add_wishlist">';
echo $this->cart->displayButton(JText::_('ADD_TO_WISHLIST'),$btnType,$this->params,$url,$wishlistAjax,'',$max,$min,'',false);
echo '</div>';
}
By :
if($this->row->product_quantity==-1){
?>
<div class="hikashop_product_stock">
<?php
echo 'product delivery will take place in 2 weeks';
if($this->params->get('add_to_cart',1)){
echo $this->cart->displayButton(JText::_('ADD_TO_CART'),'add',$this->params,$url,$this->ajax,'',$max,$min);
$btnType = 'wish';
}
if(hikashop_level(1) && $this->params->get('add_to_wishlist') && $wishlistEnabled && !$hideForGuest && $this->config->get('display_add_to_wishlist_for_free_products','1')){
echo '<div id="hikashop_add_wishlist">';
echo $this->cart->displayButton(JText::_('ADD_TO_WISHLIST'),$btnType,$this->params,$url,$wishlistAjax,'',$max,$min,'',false);
echo '</div>';
}