Select Data From Multiple Tables

Hi,
I have a number of related tables:
RGData is related to RGCrossReference
RCPPositionData is related to RCPCrossReference
RGCrossReference is also related to RCPCrossReference.
The data is returned correctly from these tables.
However, I also want to return data from another table - RComments.
How do I do this?
RComments is related to either RGData or RCPPositionData only.
Thanks.



Code Snippet
SELECT cm.CommentImage AS ViewComment, gd.PositionID AS GPositionID, cd.UniquePositionID AS CPPositionID
FROM RGData gd
INNER JOIN
RGCrossReference g
ON g.GPositionID = gd.PositionID
INNER JOIN
RCPCrossReference c
ON c.GMatchID = g.GMatchID
INNER JOIN
RCPPositionData cd
ON cd.UniquePositionID = c.CPPositionID
left outer JOIN
RComments cm
ON ((cm.CPPositionID = cd.UniquePositionID) or (cm.GPositionID = gd.PositionID))
AND cm.CommentsDate =
(SELECT MAX(CommentsDate) AS Expr1
FROM RComments
WHERE (GPositionID = g.GPositionID))
WHERE
(cd.Quantity != gd.Quantity
OR
cd.Currency != gd.Currency)
AND g.ForcedMatch = 'no';