Hello James,
>what i am trying to do is trim certain data within the field. an example is as follows:
>table field data: exampleofdata-1234
>what i want to do is trim the right side so that the data within the data field just says:
>exampleofdata.

So I'll presume you are trying to get rid if the hyphen and everything to the right of it in one particular field of a table.

>i am able to determine whether or not the data has the hyphen with a statement like:
> if right(rtrim(substr(table.field, 1, 25)),5) = '-'
>what i cannot figure out is how to get rid of those last 5 characters from the string.

If the field name is xx

*To locate the hyphen
? AT(xx,"-")   && shows the position number within the field
*expanding to pick only the stuff to the left of the hyphen
? SUBSTR(xx,1,AT("-",xx)-1)
*and to save that truncated data:
REPLACE xx WITH SUBSTR(xx,1,AT("-",xx)-1)   && operates on current record only

HTH