If you just want to see if a character is in a string then use the index function like so

my $value = '$100';

if( index($value, '$') > -1) {
  print 'found "$" in $value';
} else {
  print 'no "$" in $value';
}

__output__

found "$" in $value
[download]

And if you want to check it's at the begining of a string just check the return value e.g

my $value = '$100';

if( index($value, '$') == 0) {
  print 'found "$" at beginning of $value';
} else {
  print 'no "$" in $value';
}

__output___

found "$" at beginning of $value
[download]

See. index for more info.
HTH

_________
broquaint