Gerard,
Sounds like your connection string is not accurate. try this site for some help setting p a connection string: http://www.connectionstrings.com/?carrier=sqlserver2005

Your connection string will vary depending on how your Sql Server is set up. Might take a little trial and error.

As far as how to delete the contents of a table with SQL pass thru, here is a very simple example:

LOCAL Connectionhandle, ConnectionString

ConnectionString = "Driver=SQL Server; Server=MyComputerName\MyServerName; Database=MyDatabase"  &&  input your connection string

SQLSTRINGCONNECT(ConnectionString)

ConnectionHandle = SQLEXEC(ConnectionHandle, 'DELETE FROM MyTable WHERE 1 = 1', 'TempCursor')

SQLDISCONNECT(ConnectionHandle)