existing support for location w/ offset?

I have a community that likes to refer to positions as offsets,
e.g. 100 bases upstream of the beginning of the exon, or 5 bases after
the splice site....  They think of it as 34532+2 or 23451-23 (funny,
if you hold down the shift key when you type that, you get @#$%!-@#,
which is how I feel about it...).

Are there any exising Bio::Location classes that would make keeping
track of this info easier?

g.