Math problem with string result

[Lotondo]

Here i am again !
I partialy solved my problem but I believe it's possibile in a better way.
As I said i'm getting a string : $HOLD,-xrt4qw5101*A
Mister_e told me to use:
LATDEC var word
SerIn2 RX,BAUD,[wait("$HOLD,"),SKIP 7,DEC4 LATDEC]
This works great but the 5101 has to be divided then by 10000 and multiplied by 60, the result 30 has to be shown with LcdOut.
I was not able to make it works.
Here what I did, it works but .............. :
L1 VAR BYTE
L2 VAR BYTE
L3 VAR BYTE
L4 VAR BYTE
LATDEC VAR WORD
SerIn2 RX,BAUD,[wait("$HOLD,"),SKIP 7,L1,L2,L3,L4]
LATDEC = ((((L1-48)*1000)+((L2-48)*100)+((L3-48)*10)+(L4-48))*6)/1000
LcdOut "Result: ", " ", #LATDEC

Thanks for any further help
Lotondo