Excel 2007 : Merging information from multiple rows for duplicate entries

Help! New member so not sure if submitting in proper format, but....I have a huge worksheet (actual WS is 137,000+ rows!) that I need an "if,then" type of formula to help me collate info from duplicate entries so that I only have one line for each unique entry.

If duplicates in col. I, look at col. A to see if it also matches, then look at col. B to see if they also match, if yes, put "duplicate" in col J,

if NOT;

if info in col A matches, but info in col B does not, copy info from col B into col C, (if there are multiple matches, then col D., col E., etc)

if info in col A does NOT match, then not considered a duplicate so it would be "blank" in col J as I will need to run a pivot on all therapeutic areas/indications even though it appears to be a duplicate person. (unless I add additional cols such as Therapeutic Area (B), Indication 1 (B), Indication 2 (B) etc...) so that I truly only have one unique line per person.)

I hope this is clear......if not, let me know and I will try to clarify. I have attached an example of a portion of the actual worksheet.

Thanks in advance.