Adobe Bridge and Excel compination

This is a project in two parts. First there is to convert capital letters in a Excel file to lower-case. Only first letter in each cell shall remain capital. The excel file contains data about images. Then I need an Adobe Bridge script that pick up a number in IPTC Job identifier field and look for it in the excel file. And get the data for that number and put it in current IPTC field. The text in Job identifier field is in form of two digits and a number (fp1234). The two digits is in three different combinations fp, fn, sn, and the excel file have tree sheets, one for each of this combinations. I work on Mac and maybe its apple script that shall do the work between the two programs, but you are free to do it in best way. Best is if its possible to do it without launch excel.