how can i know a perticular quantity unit of measure is convertable or not

hi ,

depending on the delivery quantity unit of measure (likp-vrkme).

i have to convert into M2,LM,VM.

i require 2 things.

1. for exanmple let the LIKP-VRKME = 'XX'.

how can i come to know wether XX is convertable to M2,LM,VM or all of the three.

2. i need a standard unit of measure function module .

Thanks & Regads

Suresh kumar