Pattern Matching with Syntax Analyzer

Right now I'm trying to find patterns in a html page. For
example I am looking for patterns in the form of:
<td><a>...</a></td><td><a>...</a></td><td><a>...</a></td><td><a>...</a></td>


If I see that pattern I will mark the first <td>. I am using a syntax
analyzer (javacup) to do this.


My problem is this. Right now I need to detect some pattern, and I
can't seem to create a good enough set of grammar rules.


I have a Document which basically can consist of several paragraph
start tags (Div, p, span), end tags, text, a tags, and separators
(respectively b, e, t, a, s)


a document is basically a combination of those tags (I don't care
about the order in the document)
D -> DC | empty
C -> b|e|s|t|a


That rule will enable me to accept any simplified html document
However because I'm trying to match a particular pattern I must also
detect the following rules
H1 -> s b^m t* e^n s
H2 -> s b^m t* s e
H3 -> b s t* e^n s
H4 -> b s t* s e


b^m means a sequence of m number of 'b'


Is it possible to detect those rules simultaneously (I can't afford to
do it several times)?
Can anyone help me in creating these rules?

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