Option 1
pming do it like this:
Set up Roll called Skill Check
/rollunder 1d12x(p1)
Setup each skill (or conversely each group plus the smaller subset of skills that have been improved) with a [Name only - eg Vigor 5 and Swimming 7. These will report to chat only. Chance uses Vigor 5.
Setup some modifier rolls like this:
Easy
/mod 1
Very Easy
/mod 2
Hard
/mod -1
Very Hard
/mod -2
When Chance wants to do an Easy Climbing Check he clicks Vigor 5 (as he has no specific Climb skill) and this reports to chat Chance uses Vigor 5
He then clicks Easy and this adds a +1 modifier
He then clicks in the Skill Check p1 field and overwrites the existing number with a 5 and then clicks the roll button
Option 2
Setup each skill (or conversely each group plus the smaller subset of skills that have been improved) with a /rollunder 1d12x(p1) and add the skill level in the p1 field
Setup some modifier rolls like this:
Easy
/mod 1
Very Easy
/mod 2
Hard
/mod -1
Very Hard
/mod -2
When Chance wants to do a Hard Swimming Check he clicks Hard and this adds a 11 modifier
He then clicks Swimming and it rolls 1d12 and compares it to the p1 value -1
Option 3
Edit the rollunder skill and add some additional math
Set it to count successes as equal to the Dice Result if the Dice Result is equal to or less than the Skill + Modifier
Then when you roll Easy Swimming 7 and you roll an 8 it reports Success = 8, when you roll a 4 it only gives you 4 Successes and if you rolled a 9 you'd get none.
That shouldnt be too hard to do.