scrabble letter pattern search   (link)

http://www.a2zwordfinder.com/scrabbleform.html
The A2Z WordFinder Scrabble® finder is a powerful word search utility once you'e familiar with a few easy-to-understand concepts.

* The Basics - Type in the letters from your rack into the Rack letters field. If you want to build your word using parts of other words, then you can type in the pattern of letters and empty spaces from the game board into the Pattern field. Use '_', '#' or '?' characters for empty spaces. All other fields are set by default to allow this simple search to work properly.

* Limiting word length - By default, all words matching the letters and/or pattern you enter will be listed in the Search Results regardless of length. However, you can limit the length of the listed words by setting the Min. Word Length field.

* Sorting the words - The Scrabble® Search Results page can be set to sort the matching words either by length (shorter words first), by score (highest score first), or alphabetically.

* Pattern Matching - The pattern you enter can be interpreted in one of several ways, as described in the following list:
1. Match pattern exactly - The pattern will only match words of the same length or shorter (subject to the Min. Word Length limit). The words must also contain the indicated letters in the given positions. For example, the pattern "_at__" would match "bathe", "latin", "bat", and "atom". It would not match "mathematics", because it is too long.
2. Match pattern at start of word - The pattern will only match at the beginning of a word. For example, the pattern "wo" would match "work", "wood", and "worry", but not "unwound", since the "wo" in "unwound" occurs in the middle of the word.
3. Match pattern at end of word - The pattern will only match at the end of a word. For example, the pattern "an" would match "bean", "span", and "man", but not "annual", since the "an" in "annual" occurs in the beginning of the word.
4. Match pattern anywhere in word - The pattern will match anywhere in a word. For example, the pattern "or" would match "orange", "more", and "floor".

* Required Letters - When you want to specify that certain letters must be in any matching words returned, you can click on the Use Upper-Case As Required Letters? check box. Then, any letters typed into your Rack letters field that are capitalized will be required to exist in the matching results. For example, if your letters contained "TaBea", and your Min. Word Length was set to 3, then you would find "tab", "bat", "bet", and "abate" which all have t and b, but not "tea" since it does not contain the required letter "b".