Need vba code to find acc keys from bulk segment data

Dear experts

i have set of data which is having unique accounting keys, i want map accounting keys as billing value.

In column A have BT ID is repeating ID's and in column C contains description data in which accounting keys is mapped ,

i want map the account keys as per list first prioritization values

for e.g if G is first account, H is second key i want map first G, if G not in segment then go for H

but it has to map from column A unique list of segment of Sequence Number.

find the attachment Column E is my expect result