Hi Gary,
Here's a second screen shot with some revisions. Click for larger view. Formulas included below.

Test word:
Row 1 accepts the entry word or phrase in A1, then separates it into it's individual characters, starting in B1.
A1: Enter the word or string here
B1 (and Fill right to end of table): =MID($A1,COLUMN()-1,1)
Row 2 retrieves the ASCII code for each character (A = 65), converts it to the value for the upper case version of the letter if necessary, and subtracts 64 from the result (so that A or a = 1, B or b = 2, etc. This is the version used in AppleWorks, where forcing a boolean expression to act as a number did not generate the warning triangle shown in the rows in this cell.
B2 (and Fill right to end of table): =IF(B1>"",CODE(B1)-(32*(CODE(B1)>92))-64,"")
Submitted mostly for interest. It worked fine for my purposes, but it doesn't trap non-letter characters (eg. a space), so may not give the results you expect.
Row 3 uses a Lookup function (HLOOKUP in this case) to retrieve values for each letter from a Lookup table. This version, with the associated lookup table, is case insensitive, and ignores characters other than the letters in the top row of the table. The numbers in the second row are those I entered. If you want a different set of values, it's easy to edit—just enter the number you want to be substituted for each letter.
C2 (and Fill right to end of table): =IFERROR(HLOOKUP(B1,Letter value lookup :: $1:$2,2,FALSE),"")
The FALSE argument at the end specifies an 'exact-match'. Non-letter characters (or cells with no character at all) in row 1 cause a 'not found' error, trapped by IFERROR, and placing a null string in the cell.
A2: =IF(LEN($A$1)>COLUMNS(1:1)-1,"Too many letters",SUM(B2:P2))
A3: =IF(LEN($A$1)>COLUMNS(2:2)-1,"Too many letters",SUM(B3:P3))
Each provides the SUM of values in the cells in its own row (starting in column B). If the word/phrase contains more characters than there are available columns, it presents the message "Too many letters"
Letter Count:
This table provides a count of each of the letters used in the word/phrase in the main table, Test word.
A2 (and Filled right): =COUNTIF(Test word :: $1:$1,A1)
Letter value lookup:
No formulas. All values entered directly.
Regards,
Barry