Client has the requirement to derive the legal entity/company value based on project number prefix

Summary:

We have a requirement to create cross charge requisitions where The legal entity on the header level is the one paying while the legal entities in the distribution level should be the ones on behalf of which the expense is being paid. Currently, the LE derivation is based on the header LE value (mapping set).However, business wants the flexibility to derive the LE value based on the PROJECT NUMBER value at distribution level. For example -

1. If the project number starts with 'AT' (PRJ number=AT10000), then LE should 1000.

I checked the possibility of adding a mapping set, however, there is no option to add a condition based on project number 'begins/starts with'. I also tried adding account rule with a 'source' as project number, however, again I was unable to add a condition based on 'begins/starts with'.