USE statement with a variable?

I'm having some trouble modifing a script to save me tons of work. The script if from Microsoft, and it is used as step 3 in a 6 step process to move MS Great Plains users from one server to another. Anyway, the script runs on only 1 company database at a time, and for most Great Plains environments there would only be 1 or 2 company DBs. But I am administering in an ASP environment and we have over 30 company DBs to move. So, I though I would adapt thier script to iterate over each company DB to do the work (rather than creating 30 separate scripts). So I wrapped their loop with my loop to do the iteration. The problem is that T-SQL will not let me use a variable in a USE statement. I've tried to remove the USE statements, but that added a lot of complexity in the internal loop. What is the best way to do this?

Here is the modified code:

/*
** Drop_Users_Company.sql
**
** This script will remove all users from the DYNGRP in the company database
** specified. It will then drop the DYNGRP and readd the DYNGRP to the company.
** It will then add all users back to the DYNGRP based on the SY60100 table.
** NOTE: You will need to replace %Companydb% with the company database
** name.
*/
/* Instead of replacing %Companydb% (in each USE statement) with the name of the
single company database that this script is supposed to work on, I've added
@cCompany to hold the company DB name through each iteration of the outside
cursor/while loop.
*/

declare @cCompany sysname /* ADDED BY ME FOR THE OUTSIDE LOOP */
declare @cStatement varchar(255) /* Misc exec string */
declare @DynDB varchar(15) /* DB Name exec string */
declare @DYNGRPgid int /* Id of DYNGRP group */

/*
** Loop through all company databases, emptying the DYNGRP group.
*/
SET QUOTED_IDENTIFIER OFF

use DYNAMICS

/* Select all of the Great Plains database names from the DB_Upgrade table, where the DB names are conviently stored */
declare C_cursor CURSOR for select db_name from DYNAMICS..DB_Upgrade where db_name not in ('DYNAMICS')

OPEN C_cursor
FETCH NEXT FROM C_cursor INTO @cCompany
WHILE (@@FETCH_STATUS <> -1)
begin
use @cCompany
select @DYNGRPgid = (select gid from sysusers where name = 'DYNGRP')

declare G_cursor CURSOR for select "sp_dropuser [" + name+"]" from sysusers
where gid = @DYNGRPgid and name <> 'DYNGRP'

set nocount on

OPEN G_cursor
FETCH NEXT FROM G_cursor INTO @cStatement
WHILE (@@FETCH_STATUS <> -1)
begin
EXEC (@cStatement)
FETCH NEXT FROM G_cursor INTO @cStatement
end
DEALLOCATE G_cursor
/*
** Do not delete the group to attempt to preserve the permissions already
** granted to it.
*/
use @cCompany
if exists (select gid from sysusers where name = 'DYNGRP')
begin
exec sp_dropgroup DYNGRP
end
/*
** Recreate the DYNGRP group in all company databases.
*/
use @cCompany
if not exists (select name from sysusers where name = 'DYNGRP')
begin
exec ("sp_addgroup DYNGRP")
end

end
DEALLOCATE C_cursor

______________________________________
Thanks for any help you have.

I have no idea if this will work, but have you tried something like "exec('use ' + @dbName)" to loop through the databases?