Automate Labour Account to auto populate when converting a hire

Summary:

Hello - there is a requirement we are assessing:
When a hire is being converted, the Labour Account auto-populates AND is a mandatory field with * and it won't let the hire be created without it.

Example logic:

1. If Salary Basis = CA Monthly, any department, then Labour account code default to XXXX

2. If the department number is below, and salary basis is CA Hourly, then default to XXXX
Ex:
51
54
64
79
81
87
61
69
85
86
90

How would this be achieved?

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