css variable should be setted by the module

I have successfully converted a personalized style to work with phpbbforum in drupal page mode.
If u are interested I just made a script to edit my previous css adding #phpbbforum-page before every declaration, and adding something like this at the top of stylesheet.css:

#phpbbforum-page ul {
list-style-type: none;
list-style-image: none;
background: none;
}

#phpbbforum-page li {
list-style-type: none;
list-style-image: none;
background: none;
}

Maybe others reset should be done for this and/or other tags..

Now I see all ok, but I have to edit images paths handy to work in drupal page because css variables like:
{IMG_BUTTON_TOPIC_LOCKED_SRC}
are not setted.

This is the script I wrote:

#!/bin/sh

# Convert styles to phpbbforum

PREPOST="#phpbbforum-page"

if [ -z $1 ];then
        echo "Usage $0 file.css"
        exit 1
fi
CSSFILE=$1

while read LINE
do
DIRECTIVE=`echo $"$LINE" | grep "{"`
if [ -z $"$DIRECTIVE" ];then
        # NORMAL LINE
        echo $"$LINE"
else
        # FOUND CODE TO EDIT
        ONELINE=`echo $"$LINE" | grep "}"`
        if [ -z $"$ONELINE" ];then
                # MULTI LINE CODE
                DIRECTIVE=`echo $"$DIRECTIVE" | sed s/{//`
                DD=`echo $"$DIRECTIVE" | cut -d',' -f1`
                while [ ! -z $"$DD" ]
                do
                        echo -n $PREPOST $"$DD "
                        DIRECTIVE=`echo $"$DIRECTIVE" | cut -d',' -f2-`
                        if [ $"$DD" == $"$DIRECTIVE" ];then
                                DIRECTIVE=""
                                DD=""
                        else
                                DD=`echo $"$DIRECTIVE" | cut -d',' -f1`
                                echo -n ", "
                        fi
                done
                echo " {"
        else
                # ONE LINE CODE
                echo $PREPOST $"$DIRECTIVE"
        fi
fi
done < $CSSFILE

exit 0

Tnx for your good work