User regular expression to find image named @"daoju_XX_65.png",XX is a Int

User regular expression to find image named @"daoju_XX_65.png",XX is a Int

In my Ios project,I would like to use regular expression to find image in
bounds named like @"daoju_XX_YY.png", XX is a int num I want to ignore ,
YY is a imageID that I know, for example:I can make sure that there is
only one image named that @"daoju_XX_62.png",NSString
*imgName=@"daoju_XX_62.png",how can I deal with imgName so that I can get
the image with [UIImage imageNamed:imgName]?