Sample for DMS
#Longitude: 99°51'05.2"E
#Latitude: 6°19'19.3"N
Sample for DD
#Longitude: 99.8514444444444
#Latitude: 6.32202777777778
Excel formulas
#Longitude (B2)
=(MID(B2,1,FIND("°",B2)-1)+(MID(B2,FIND("°",B2)+1,FIND("'",B2)-FIND("°",B2)-1)/60)+(MID(B2,FIND("'",B2)+1,FIND("""",B2)-FIND("'",B2)-1)/3600))*IF(OR(MID(B2,FIND("""",B2)+1,1)="E",MID(B2,FIND("""",B2)+1,1)="N"),1,-1)
#Latitude (D2)
=(MID(D2,1,FIND("°",D2)-1)+(MID(D2,FIND("°",D2)+1,FIND("'",D2)-FIND("°",D2)-1)/60)+(MID(D2,FIND("'",D2)+1,FIND("""",D2)-FIND("'",D2)-1)/3600))*IF(OR(MID(D2,FIND("""",D2)+1,1)="E",MID(D2,FIND("""",D2)+1,1)="N"),1,-1)