[Genome] Download first intron sequences

[Montemayor, Celina]

Hi,
I was wondering if I could get some advice regarding how to download the coordinates of the frist introns of my list of genes (I need a BED file)? I used the table browser to paste my gene IDs and download intron sequences; the output I obtained looks like this:
 
chr1	 136014280	 136014811	      NM_016749_intron_5_0_chr1_136014281_f	
 
Is there a way for me discriminate which are the coordinates corresponding to the first introns?
 
Thanks for your help,
 
Celina Montemayor, MD
Graduate Student, Pereira lab
Baylor College of Medicine