I have few regulat expression code that need to be find and replaced -Need extend script to automate

 am copy pasting them all these expression one by one in sequence.

i have this extend script code, but where should i have to keep the search and replace text?

function FindAndReplaceString(activeDoc, flow, findString, replaceString, considerCase) {

var tr = new TextRange();
var restoreTR, frame = 0;
var loopCounter = 0, replacementCounter = 0;
var findParams = new PropVals();

//if the flow object is not valid, assume the main flow
if(activeDoc.ObjectValid() && !flow.ObjectValid()){
flow = activeDoc.MainFlowInDoc;
}

//get the first text frame in the flow, a starting point to
//find the first paragraph
if(flow.ObjectValid()){
frame = flow.FirstTextFrameInFlow;
}

//At this point, if we don't have a frame object, might as well abort.
if(!frame.ObjectValid()){
Alert("Could not find a starting point for the search. Cannot continue." , Constants.FF_ALERT_CONTINUE_WARN);
return replacementCounter;
}

//store the original text selection as an amenity to restore after the action.
restoreTR = activeDoc.TextSelection;

//now, set up the starting text range as the very beginning
//of the flow. We'll move straight from beginning to end.
tr.beg.obj = tr.end.obj = frame.FirstPgf;
tr.beg.offset = tr.end.offset = 0;

//set up our find parameters. We want to configure it to look
//for a string and perhaps be case sensitive. We don't need
//the find to wrap because we are controlling the flow from
//beginning to end.
findParams = AllocatePropVals(2);

findParams[0].propIdent.num = Constants.FS_FindText;
findParams[0].propVal.valType = Constants.FT_String;
findParams[0].propVal.sval = findString;

findParams[1].propIdent.num = Constants.FS_FindCustomizationFlags;
findParams[1].propVal.valType = Constants.FT_Integer;
if(considerCase){
findParams[1].propVal.ival = Constants.FF_FIND_CONSIDER_CASE;
}
else{
findParams[1].propVal.ival = 0;
}

//initialize the errno global, which will be used to
//track the progress of the find and replace
FA_errno = Constants.FE_Success;

//and do an initial find to get started.
tr = activeDoc.Find(tr.beg, findParams);

//now, run the find and replace loop as long as we keep finding things.
//The loop counter is just an emergency back door in case something
//goes critically wrong and causes an endless loop.
while(FA_errno === Constants.FE_Success && loopCounter++ < 1000){

//set up the text range to clear the original text
activeDoc.TextSelection = tr;

//clear it
activeDoc.Clear(0);

//insert the new text. We should be able to use the
//original beginning of the text range where the old text was
//found.
activeDoc.AddText(tr.beg, replaceString);

//now, lets jimmy the text range in memory to place it directly
//after the string we just inserted, so the find picks back up after that.
tr.beg.offset += replaceString.length;

//increment our return counter
if(FA_errno === Constants.FE_Success){
replacementCounter++;
}

//...and find the next instance. We'll reset FA_errno again just in case
//something screwy happened while we were replacing text.
FA_errno = Constants.FE_Success;
tr = activeDoc.Find(tr.beg, findParams);
}

//we're done. Restore the document to it's original area of display
activeDoc.TextSelection = restoreTR;
activeDoc.ScrollToText(restoreTR);

return replacementCounter;
}