KABUL, Afghanistan - A newborn girl left abandoned on the side of the road in southern Afghanistan has been adopted by a childless Afghan couple.

"We have named her Arya [which means happiness], and we will take care of her forever," the adoptive father, Mohammad Zahir, a 29-year-old shopkeeper from Ghazni, Afghanistan, said Thursday. "She has completely changed our lives. We are so happy. The whole family has been supportive of our decision."

Zahir has been married for four years, but he and his wife have been unsuccessful in their attempts to have children.

After a visit to a Ghazni hospital, however, he and his wife have their family.

"A man, Mohammad Zahir, contacted us and asked if his family could take care of the baby," Baz Mohammad Himat, director of health in Ghazni, said. "They promised to take care of her for the rest of their lives.

"This family was on a waiting list with this hospital for any unwanted baby."

Polish soldiers who discovered the baby on the Afghan roadside initially named her Pola, after Poland. They found her wrapped in a towel Sept. 19 while they were checking a route near their Waghez military base for safety, Defense Ministry spokesman Janusz Walczak told The Associated Press.

The soldiers were initially suspicious when they discovered the baby because there is a risk of hidden roadside bombs across Afghanistan.

After the troops found the baby, she was brought to a medical center at their base. The soldiers then bought the girl baby formula, a bottle and a bib.

ABC News' Kevin Dolak contributed to this report.