send subtitle file to external player

Hi, I've been trying to use bino as an external player for 3D movies.. only thing is bino needs to open both the media file & the subtitle file at once in order to show subs...

I was wondering if there's any way to get the filename that xbmc sends in form of a string and change its extension (to the subs one) in order to send them both to bino...

for instance:

<playercorefactory>
<players>
<player name="Bino3D" type="ExternalPlayer" audio="false" video="true">
<filename>/Applications/Bino.app/Contents/MacOS/Bino</filename>

<args>--input=left-right-half "{1}"

"$tring {1} minus .*** + .srt" >>> THIS IS MADE UP!! JUST AN EXAMPLE OF WHAT I'M LOOKING FOR....

--output=red-cyan-dubois -f</args>

<hidexbmc>true</hidexbmc>
<playcountminimumtime>1800</playcountminimumtime>

...blah blah

</playercorefactory>