.module.title3 h3.modtitle:before {
    background: none repeat scroll 0 0 #960723;
    color: #FFFFFF;
    content: "+";
    display: inline-block;
    font-size: 21px;
    height: 20px;
    line-height: 15px;
    margin-right: 5px;
    text-align: center;
    width: 20px;
}

.module.title3 h3.modtitle:before {
    background: #960723 url("../images/your_background.png") 0 0;
    color: #FFFFFF;
    content: "";
    display: inline-block;
    font-size: 21px;
    height: 20px;
    line-height: 15px;
    margin-right: 5px;
    text-align: center;
    width: 20px;
}