[devote]

тогда нужно так примерно делать

var re = /^[a-zA-Z\d]*([a-z]+[A-Z]+\d+|[A-Z]+[a-z]+\d+|[a-z]+\d+[A-Z]+|[A-Z]+\d+[a-z]+|\d+[a-z]+[A-Z]+|\d+[A-Z]+[a-z]+)[a-zA-Z\d]*$/;

alert( re.test( "HGf234k2" ) );

alert( re.test( "Ggrgr4FFFF3342r4rr4rFFFFffGGG" ) );