Sample string

`Rpt#_SPACE_MINVTAN<br_SPACE_/>
_SPACE__SPACE__SPACE__SPACE__SPACE_01212_SPACE__SPACE_`

There is a line break at the end of line one. Line two always has 5 spaces, then a 5 digit number, then two more spaces.... Now there is more random text before what I pasted, and more random after. 

The number of \_SPACE\_ after the customer number must be 2 or more. 

I guess what I'm looking for is this: 

Find in the middle of a large string `_SPACE__SPACE__SPACE__SPACE__SPACE_012345_SPACE__SPACE_`

Extract the number into a variable.