The problem was that the like clause, as formed, was no enclosed in single quotes. So, if you try the following, I think it will work:
=SQL.REQUEST("DSN=Baan;UID=xxxxx;PWD=xxxxx;Database=baandb"||2| "SELECT a.t_copr FROM ttiitm001100 a WHERE a.t_item LIKE '
It may be hard to read, so here is the last part expanded:
You probably already know this, but I'll throw it out anyway. In SQL Server LIKE clauses, use % to mean any characters. Thus
matches words starting with cha.
I hope this helps.