Timecode parsing for user input

I have a script that allows users to enter timecode as a string, and I wanted it to perform the same as the Timecode inputs in the rest of the program: if they type "1..." I want it to register as 1:00:00:00 without them having to type a correctly formatted string.

This. Took. Ages. I descended deep into the regex underworld, but I'm happy to say that I managed to placate the JS gods with my mad skillz on the lyre and returned victorious. So for any other young traveller preparing to take the journey, here's what I worked out. If you have suggestions, please, let me know.

function parseTimeString(theString, comp) {    comp = app.project.activeItem; //need an active comp in order to get the frameDuration    if (comp) {        theString = "" + theString;        //allows user to lazily enter timecode, eg. to enter 1 minute you type 1.. rather than 0:1:0:0        //this took ages to work out..        var hrsStr = theString.match(/(\d+)\D\d*\D\d*\D\d*$/); //matches  "0:1:2:3" and "0..." and returns '0'        var minStr = theString.match(/(\d+)\D\d*\D\d*$/); //matches "0:1:2:3" , "1,2.3" and "1.." and returns 1        var secStr = theString.match(/(\d+)\D\d*$/); //and so on..        var frmStr = theString.match(/(\d+)$/);        //convert the strings to time values        var hrs = hrsStr            ? parseInt(hrsStr)            : 0;        var min = minStr            ? parseInt(minStr)            : 0;        var sec = secStr            ? parseInt(secStr)            : 0;        var frm = frmStr            ? parseInt(frmStr)            : 0;        //return the result as time, measured in seconds        return 3600 * hrs + 60 * min + sec + comp.frameDuration * frm;    }    return false;
}