Isolating values from a string

Hi Experts,

I am using Webi in SAP BusinessObjects Business Intelligence 4.1 SP 7.

I am faced with the following challenge.
In one of the fields is a combination of the following values:

1234567
INM87654321

or

INM87654321
1234567

or

INM87654321

I am just interested in displaying the value beginning with INM.
How can I isolate this value and display just this value?

TIA,
Henning