Ok, here we go... Assuming that you have the company name in a variable and the fact that you're using a version of T-SQL that cannot use functions, here's how I'd do it...

[font="Courier New"]

--===== Company name is in a variable

DECLARE @CompanyName VARCHAR(256)

 SELECT @CompanyName = 'A & B Cleaners' 

  PRINT @CompanyName --Just for verification... you can remove this line

--===== Using a "Tally" table as a loop driver, remove all characters that

     -- are NOT in the in range of A to Z (upper or lower case)

 SELECT @CompanyName = STUFF(@CompanyName,PATINDEX('%[^A-Z]%',@CompanyName),1,'')

   FROM dbo.Tally t

  WHERE t.N <= LEN(@CompanyName)

    AND SUBSTRING(@CompanyName,t.N,1) LIKE '[^A-Z]'

--===== Grab just the left six characters of what remains.

 SELECT @CompanyName = LEFT(@CompanyName,6)

--===== Display the result (just for verification... you can remove this line)

  PRINT @CompanyName[/font]

If you don't have a Tally table, please see the article at the following URL for how to build one, what it is, and how it works. It's a very useful tool that can frequently be used to replace loops.

http://www.sqlservercentral.com/articles/TSQL/62867/

If you need to do this to a whole table column, please post back.