RobE has it right for you...but another way...

{[(total PA available)* (160/162)] * (games played so far / 160) } * (usage / 100)

For instance:
at 100 games into RT 2003 season
Pudge Rodriguez is at 105 pct usage
he actually had 578 PA's in 2003

thus:
578 * (160/162) * 100/160 * 105/100 = 374 PA's
Which you could find if you looked on the page described by RobE

This works for you if you want to check and be sure you aren't being cheated by PB.

You have to put in the 160/162 because we play a 160 game season and PB makes this adjusment in calculating your player usage.

Check it out.

During the season leave the 160/162 but change the other 160 to the games on which the actual PA's are based so that if 50 games into the season Pudge had 200 PA's (real life) and 180 in the first 30 games of RT PB:

180 * 160/162 * 30/50 * pct use/100 = PA's

Is this what you wanted or did you just want the page RobE referred to?